How to Disable Hibernation and Delete hiberfil.sys File in Windows 7
Method :- 1 If you use the power options in Control Panel, you can turn off hibernation. However, the hibernation file remains [It May take a lot of space in your Hard Drive ]. To disable hibernation and delete the hibernation file, you have to use powercfg command line tool. Follow these steps.
1)Using the Command Prompt might be the easiest way to enable or disable Hibernation. Click on Start and type CMD into the search box and it will be listed under programs. Right-click on the icon and select Run as administrator.
2) Type this command. powercfg -h off
3) Type exit to come out of Command Prompt
That’s it. If you ever want to turn it back on. Just type powercfg -h on
METHOD :- 2 Enable or Disable Hibernate Through Command Prompt
Using the Command Prompt might be the easiest way to enable or disable Hibernation. Click on Start and type CMD into the search box and it will be listed under programs. Right-click on the icon and select Run as administrator.

The Command Prompt opens and you will use the following to enable Hibernation.
powercfg /hibernate on

Type in the following to disable hibernation.
powercfg /hibernate off

METHOD :- 3 Manage Hibernation Through Control Panel
1) Click on Start and open Control Panel then click on Power Options.

2) On the left side click on Change when the computer sleeps.

3) Now click on Change advanced power settings. In the Advanced Power Options window expand the Sleep tree then expand Hibernate after and change the minutes to zero to turn it off. Or you can specify the amount of minutes you want to pass before it goes into hibernation. After you’ve made your selection click Apply and Ok then close out of the remaining screens.

Where is Hibernate?
What if you try the command line option to turn it on and Hibernate mode still isn’t available? Then what you’ll want to do is disable Hybrid Sleep by expanding Allow hybrid sleep and turning it Off.

Now you should have Hibernate and Sleep as part of the power options in the start menu and will also be an option when you hit Ctrl+Alt+Del.

METHOD :- 4 Disable Hibernate Through Regedit
Note: Changing registry values can cause your computer to become unstable or stop functioning and is only recommended for experienced users.
Now that the disclaimer is out of the way…you might want to completely disable Hibernate mode through a registry edit. Open the Registry and browse to HKEY_LOCAL_MACHINE \ SYSTEM \ CurrentControlSet \ Control \ Power and change both HiberFileSizePercent and HibernateEnabled value data to zero. After you’ve made the changes close out of the Registry Editor and restart the machine.

How to use the Bootrec.exe tool in Vista or Win 7

To run the Bootrec.exe tool, you must start Windows RE. To do this, follow these steps:
1) Put the Windows Vista or Windows 7 installation disc in the disc drive, and then start the computer.
2) Press a key when you are prompted.
3) Select a language, a time, a currency, a keyboard or an input method, and then click Next.
4) Click Repair your computer.
5) Click the operating system that you want to repair, and then click Next.
6) In the System Recovery Options dialog box, click Command Prompt.
7) Type Bootrec.exe, and then press ENTER.

Note To Boot the computer from the Windows Vista or Windows 7 DVD, the computer must be configured to boot from the DVD drive.

Bootrec.exe options
The Bootrec.exe tool supports the following options. Use the option that is appropriate for your situation.

Note If rebuilding the BCD does not resolve the startup issue, you can export and delete the BCD, and then run this option again. By doing this, you make sure that the BCD is completely rebuilt. To do this, type the following commands at the Windows RE command prompt:

bcdedit /export C:\BCD_Backup
c:
cd boot
attrib bcd –s -h -r
ren c:\boot\bcd bcd.old
bootrec /RebuildBcd

/FixMbr
The /FixMbr option writes a Windows 7 or Windows Vista-compatible MBR to the system partition. This option does not overwrite the existing partition table. Use this option when you must resolve MBR corruption issues, or when you have to remove non-standard code from the MBR. {Bootrec.exe /FixMbr}

/FixBoot {Bootrec.exe /FixBoot}
The /FixBoot option writes a new boot sector to the system partition by using a boot sector that is compatible with Windows Vista or Windows 7. Use this option if one of the following conditions is true:
a) The boot sector has been replaced with a non-standard Windows Vista or Windows 7 boot sector.
b) The boot sector is damaged.
c) An earlier Windows operating system has been installed after Windows Vista or Windows 7 was installed. In this scenario, the computer starts by using Windows NT Loader (NTLDR) instead of Windows Boot Manager (Bootmgr.exe).

/ScanOs {Bootrec.exe /ScanOs}
The /ScanOs option scans all disks for installations that are compatible with Windows Vista or Windows 7. Additionally, this option displays the entries that are currently not in the BCD store. Use this option when there are Windows Vista or Windows 7 installations that the Boot Manager menu does not list.

/RebuildBcd {bootrec /RebuildBcd}
The /RebuildBcd option scans all disks for installations that are compatible with Windows Vista or Windows 7. Additionally, this option lets you select the installations that you want to add to the BCD store. Use this option when you must completely rebuild the BCD.

--------------------------------------------------------------------------------
APPLIES TO
Windows Vista Ultimate
Windows Vista Enterprise
Windows Vista Business
Windows Vista Home Premium
Windows Vista Home Basic
Windows Vista Business 64-bit Edition
Windows Vista Enterprise 64-bit Edition
Windows Vista Home Premium 64-bit Edition
Windows Vista Home Basic 64-bit Edition
Windows Vista Ultimate 64-bit Edition
Windows 7 Enterprise
Windows 7 Enterprise N
Windows 7 Home Basic
Windows 7 Home Premium
Windows 7 Home Premium N
Windows 7 Professional
Windows 7 Professional N
Windows 7 Starter
Windows 7 Starter N
Windows 7 Ultimate
Windows 7 Ultimate N

Device Manager and Network Connections may be blank after you install Windows XP Service Pack 3

Solution 1
1. Restart the computer in safe mode. To restart the computer in safe mode, follow these steps:
a. Click Start, and then click Shut Down.
b. In the Shut Down Windows dialog box, select Restart in the What do you want the computer to do list, and then click OK.
c. After the computer restarts but before Windows XP starts, press F8.
d. Use the arrow keys to select the Safe Mode option, and then press ENTER.
2. Click Start, and then click Run.
3. Type regedit in the Open box, and then press ENTER.
4. Locate and then click the following registry subkey:
HKEY_LOCAL_MACHINE\SYSTEM
5. On the Edit menu, click Find.
6. In the Find what box, type the following text:
$%&'()*+
7. Click Find Next.
8. Right-click the registry subkey that begins with "$%&'()*+," and then click Delete.
9. Click Yes to confirm the deletion.
10. Press F3 to search for the next registry subkey.
11. Repeat steps 7 through 8 to delete each registry subkey that contains the text "$%&'()*+."
12. Exit Registry Editor.
13. Restart the computer.
APPLIES TO
• Microsoft Windows XP Service Pack 3, when used with:
o Microsoft Windows XP Professional
o Microsoft Windows XP Home Edition

Solution 2

Click on the Link Mention Below to Download the Patch
http://support.microsoft.com/kb/953979

Or

http://www.softwarepatch.com/windows/device-manager-empty-patch.html

Solution 3

Issue is expected to be caused by Norton
• Uninstall Norton Antivirus 2008
• Backup this registry location: HKLM\SYSTEM\ControlSet001\Enum\Root\LEGACY_LIVEUPDATE_NOTICE
• Delete this registry location: HKLM\SYSTEM\ControlSet001\Enum\Root\LEGACY_LIVEUPDATE_NOTICE
• Reboot – Issue will be resolved (need to look at Device Manager to verify)
• If resolved, Reinstall Norton AV 2008

Improving performance of Windows XP by disabling Windows XP-services

Use the Services Management Tool for improving performance of Windows XP (Control Panel, Administrative Tools, Services or Type SERVICES.MSC in the RUN box and press Enter)

Services to disable to recover system resources
The list below shows multiple services which are reasonably safe to disable.

CAUTION

PLEASE read carefully the service description before disabling a service! Keep in mind that possible future error messages can be created (and solved...) by changing the startup type of the services. If there is any doubt about the effect of disabling a service, rather keep it unchanged! If certain functionalities don't function properly anymore, just reactivate the service by changing the startup type to Automatic or Manual. Do not disable to many services at once, but take some time to investigate the individual changes and do not disable services where other services depend on! If you hesitate disabling a service permanently, change the startup type to Manual first.

1) Alerter: Most times this service is not used. It takes care of administrative alerts over a network for administrative purposes.

2) Automatic Updates: Downloading and installing Windows updates. If you think you don't need this service, you can disable it. Remember that the Windows update website doesn't work anymore without this service, since the introduction of Windows XP SP2. I advise to keep it unchanged. To work properly, the Automatic Updates service also needs Background Intelligent Transfer Service, Event Log and the Cryptographics Services.

3) Computer Browser: This services lists all computers in a network and gives this information to other computers in the network, when asked for. This makes browsing on the network faster. There is no need for this service, and especially not if you don't have a network situation. With this function disabled, you are still able to browse your network!

4) Distributed Link Tracking Client: This service is only applicable when you make use of the NTFS file system. If you don't use this file system, you can switch off this service. This services makes sure that linked files on different volumes (possibly somewhere on the network) stay connected. If a file has been moved to another location, the link will be updated by this service. There is probably no need at all to for this services on your computer, so disable it.

5) Error Reporting Service: Enables the option to report system errors to Microsoft. There is no need to do this, enough reason to disable this service.

6) Event Log: This services logs issues in the log files, which can be viewed with the Event Viewer (Control Panel, Administrative Tools, Event Viewer). Although you might think it's not useful, do not disable this service but keep it automatic.

7) Fast User Switching Compatibility: If you don't need the fast switching between user accounts, disable this function. Fast switching of user accounts makes it possible to leave your application open without saving your data. If not needed, don't use this function, it doesn't always work properly.

8) Help and Support: Without this service, the Windows Help and Support center will not be available. If you don't need this help, switch this service to manual.

9) IMAPI CD-Burning COM Service: This function is used to able to burn CD-ROM's with the Windows Explorer (copy-paste files to your CD burner). If you don't have a CD-burner, you can disable this service (or switch to manual). It is possible that this service causes troubles in combination with other burning software.

10) Indexing Service: With this indexing service, you are able to search faster on your computer. The faster searching comes at a cost: the indexing of the content, which slows down your computer. This services is not needed, I advise to disable it for better overall performance.

11) IPSEC-services: Manages IP security policy, possibly not needed for your system.

12) Messenger: The Messenger service makes it possible sending messages over the network (it has nothing to do with Live Messenger). This function works by the following command: NET SEND 127.0.0.1 Hello (Start, Run,..), a new message Window should appear if this service is enabled. This service is also available from the internet, which makes it possible to receive strange messages: reason enough to disable this service.

13) NetMeeting Remote Desktop Sharing: This service provides the possibility to invite others to access your computer as a remote desktop. There is no need for this service. For security issues, you better disable this option.

14) Performance Logs and Alerts: The making off performance logs will probably lower your systems performance: reason enough to disable it, especially if you never read the log files.

15) Portable Media Serial Number Service: Needed to reed the serial number of any portable media player. If this function is disabled, there is a chance not to open (downloaded) protected content. You probably can disable this service without any noticeable consequences.

16) Print Spooler: Necessary for printing. If you don't want to have the option to print, you can disable it.

17) Protected Storage: This service provides the possibility to safe passwords (email, websites, dial up,..). Remember that passwords can be easily retrieved with freeware software [I prefer to keep this option on automatic].

18) QoS RSVP: QoS is probably not needed for your network traffic, so you can disable this service.

19) Remote Access Auto Connection Manager: If you are getting troubles with your internet connection, leave this service on automatic. If you are using a router: disable this service.

20) Remote Desktop Help Session Manager: If you don't need remote assistance (the other person controls your computer by your invitation), disable this function.

21) Remote Registry: Thanks to this service, external users are able to make changes to the registry keys over the network connection. This option is not safe, therefore it is better to disable it.

22) Routing and Remote Access: If there is no need to dial in by others into your computer, disable this service.

23) Security Center: Service Pack 2 provided Windows XP with the Security Center. The Security Center monitors the proper functioning of your system security (Windows updates, firewall and virus scan). If something is not working properly, you will be informed continuously. I can't imagine why you can't do it yourself, reason enough to disable it.

24) Server: For sharing local files and printers with other computers on your network. If there is no need to share, disable this service.

25) Shell Hardware Detection: Essential for automatic playing of connected devices (memory cards, CD/DVD).

26) Smart Card: No reason to run this service when you don't use a smart card (e.g. for telebanking purposes).

27) System Event Notification: Almost never used. Leave the service on automatic if you have a network or a portable PC, else disable it.

28) System Restore Service: This service makes it possible to restore your system to an earlier date if something did go seriously wrong. This service consumes a lot of your system performances while the System Restore doesn't always function properly (and you can loose data!). Disabling this service is a relief for the system performances!

29) Task Scheduler: This service enables automatic scheduled tasks (like regularly downloading of virus definitions, but also the prefetching which improves sytem performances!). Many applications need this service. If you prefer to do everything yourself, you can disable this service. I prefer automatic.

30) Theme's: If you don't need the XP look, disable this function [I prefer automatic].

31) Windows Audio: needed for playing sounds, up to you.....

32) Windows Firewall (ICF) / Internet Connection Sharing (ICS): This services provides your computer with a software firewall for your internet connection. You can disable the firewall service if you use a third party firewall (do NOT go online without a firewall!). Besides the firewall function, the service provides you with the possibility to share the internet connection with other computers, which is not needed when your network is provided with a router.

33) Windows Image Acquisition (WIA): This service is used for transferring images from your camera/web cam or scanner. Leave this service on manual if you have one of those devices, else disable the service.

34) Windows Installer: Needed for installing MSI setup files. Do not disable this option, else windows updates won't be installed.

35) Windows Search (if installed): For indexing and quickly extended searching through (personal) files. If this search feature is not used, it is better to disable it. Remove the shortcut to Windows Search in the folder Startup (Start, All programs) and deactivate the toolbar Windows Search Toolbar (right click the taskbar, sub Toolbars) as well.

36) Windows Time: If you prefer to keep you system clock up to date manually (if needed.....), there is no need for an automatic update: disable it as you wish.
Wireless Zero Configuration-service: Needed for automatic configuration of your wireless network connection. If you don't have any wireless network adapter, disable this service.
WMI Performance Adapter: No need for performance information, only the performances? Disable this service.

37) Wireless Zero Configuration-service: Needed for automatic configuration of your wireless network connection. If you don't have any wireless network adapter, disable this service.

38) WMI Performance Adapter: No need for performance information, only the performances? Disable this service.

Improving performance of Windows Vista by disabling Windows Vista-services

How to Disable services

Type the command SERVICES.MSC in the search field of the Start menu will start the management console to tweak the services (the management console is also available by Administrative Tools in the Control Panel, option Services). In the management console, a description of each service is shown, including the relationship (dependencies) between the different services.

Services to disable to recover system resources

The list below shows multiple services which are reasonably safe to disable.

CAUTION

PLEASE read carefully the service description before disabling a service! Keep in mind that possible future error messages can be created (and solved...) by changing the startup type of the services. If there is any doubt about the effect of disabling a service, rather keep it unchanged! If certain functionalities don't function properly anymore, just reactivate the service by changing the startup type to Automatic or Manual. Do not disable to many services at once, but take some time to investigate the individual changes and do not disable services where other services depend on! If you hesitate disabling a service permanently, change the startup type to Manual first.

1) Application Experience: Investigates the compatibility of older programs and searches for updates for known problems. Although disabling this service doesn't have negative side effects, it is better to keep it unchanged.

2) Computer browser: Tracks the computers (and files) on the network and maintains an updated list. This service is only useful in case of a LAN where the computers share files with each other. After disabling this service, it is still possible to browse the network. The service depends on the services Server and Workstation.

3) Desktop Window Manager Session Manager: Necessary for the new Aero Glass-interface. Only disable this service if the new Aero Glass-interface is not used.

4) Diagnostic Policy-service and Diagnostic System Host: For the detection of problems, troubleshooting and presenting known resolutions for Window components. If there are no problems expected anymore, it is safe to disable the service.

5) Distributed Link Tracking Client: Makes sure that linked files on multiple computers in a network stay linked. This service can be disabled safely, because in most home situations, this option is not used at all.

6) Function Discovery Provider Host: Makes it possible to share network shares with other computers. If this service is disabled, the shared files are no longer visible by other computers in the network. Disabling this service is also possible by disabling the option Network discovery in the Network and Sharing Center in the Control Panel.

7) Function Discovery Resource Publication: This service publishes the shared files and printers so they can be discovered by other computers in the network. Disable this service if it is not necessary that other computers are able to discover shared resources. This service can be disabled as well by disabling the option Network discovery.

8) Human Interface Device Access: Support for a multimedia device like a remote control and hot buttons on keyboards (like the volume and e-mail button).

9) Internet Connection Sharing (ICS): For sharing the internet connection with other computers in the network (this computer operates as a router). If a router is used to connect all the computers to the internet, this service is not needed.

10) IP Helper: Support for a IPv6 connection over a IPv4 network. IPv6 is the new connection type of the future which makes it possible to give every computer connected to the internet a unique IP address in stead of one single IP address for the internet connection (where the connected router uses special IP addresses for home use). The use of IPv6 has some advantages (but also disadvantages) but at the moment, there are not many providers supporting this new connection type. If IPv6 is not supported or used, disable the service for security reasons.

11) Network List-service and Network Location Awareness: Without these services, the network connection still works fine, but it is no longer possible to show the status in the system tray and the Network and Sharing Center. To keep this functionality, it is better not to disable these services.

12) Offline Files: Makes the network shares also available when the share is offline. The edited files will be synchronized automatically the first time the network share has become available. If this option is not desired, then it is better to disable this service.

13) Portable Device Enumerator Service: Enforces group policy for removable mass-storage devices. If this service is disabled, it is no longer possible to read/write protected devices. If it is not necessary to access removable mass-storage device using group policy, it is safe to disable the service (the removable media will still be accessible by applications which don't rely on this service).

14) Print Spooler: Necessary for loading a print job into memory for later printing. If there is no printer connected to the computer, this service can be disabled. But remember that it is not possible to add printers if the service is not running! If a printer is already installed, this printer will probably have a service running as well. [ I Would Suggest not to Disable this Services]

15) Remote Access Connection Manager: Necessary for managing dial-up and virtual private network (VPN) connections. If the computer is connected to a router and no VPN connection is needed, this service can be disabled safely. Because the service Remote Access Auto Connection Manager depends on this service, it can be disabled as well.

16) Remote Registry: Thanks to this service, external users are able to make changes to the registry keys over the network connection. This option is not safe, therefore it is better to disable it.

17) Routing and Remote Access: Disable this service if it is not desired that other computers are able to dial in to get access to the local network.

18) Server and Workstation: Necessary to share files and printers with other computes within a network. If this is not the case, it is safe to disable these services. After disabling the services, it is still possible to access shared folders on other computers. If these services are disabled, it is no longer possible to activate the option File sharing in the Network and Sharing Center.

19) Shell Hardware Detection: This service starts the auto play of devices like DVD drives and memory cards. This service is also responsible for showing a window with the options which action to take with a certain type of file. If you don't like this function, disable this service. Because the service Windows Image Acquisition (WIA) depends on it, it has to be disabled as well.

20) Superfetch: Tracks the running programs, and improves the performance of the frequently used programs over time. Because this service is improved significantly compared to Windows XP, it is not wise to disable the service (disabling causes no problems).

21) System Event Notification--service: Monitors and notifies system events like network activity or the energy status for laptop computers. Disabling this service has probably no negative side effects, but this can be different for each situation.

22) Tablet PC Input-service: Enables the Tablet PC and ink functionality. If the computer is not a Tablet PC, it is safe to disable the service.

23) Task Scheduler: It is not possible to disable this service. That's no problem, because the most scheduled tasks won't run if the computer is actively used by the user. The settings of the scheduled tasks can be changed by the Administrative Tools in the Control Panel, Task Scheduler. The possibilities to add and change tasks have improved significantly compared to Windows XP.

24) TCP/IP NetBIOS Helper: Offers support for the (rarely used) NetBIOS over TCP/IP. Disabling the service will probably not casue any problems.

25) Terminal Services: As long as Remote Desktop is not used, it is safe to disable this service.

26) Themes: Disable this service if there is no need for the visual effects like the new Aero interface. Disabling is only advised for slow computers because the new interface is one of the most important reasons to upgrade to Windows Vista. To disable visual settings manually, go to System in the Control Panel, Advanced system settings (in the left task pane), tab Advanced, button Settings (sub Performance).

27) Windows Image Acquisition (WIA): For transferring images from a scanner or camera to the computer.

28) Windows Audio and Windows Audio Endpoint Builder: Keep these services enabled to be able to hear the audio effects.

29) Windows Defender: Additional scanning software for unwanted software. If this service is disabled, disable the automatic start up of the tool Windows Defender as well, else the error message 0x800106BA appears. This error message can bed solved by disabling the automatic stat up with the tool MSCONFIG (tab Startup). After disabling the service, Windows Defender is no longer accessible by the Control Panel.

30) Windows Error Reporting-service: Generates an error message when a program no longer responds. If this service is disabled, error reporting is no longer possible and existing solutions are not delivered anymore.

31) Windows Firewall: If a software firewall is installed, the Windows firewall is no longer needed. For safety reasons, it is better not to disable it.

32) Windows Media Center Service Launcher: Starts other Media Center-services at startup if TV is enabled within Windows Media Center. The startup type of this service is automatic but delayed, which causes no delays at startup. If Windows Media Center is not used, it is safe to disable this service and the other Media Center services.

33) Windows Media Player Network Sharing-service: If it is not desired to share Windows Media Player libraries, it is safe to disable this service.

34) Windows Search: Provides content indexing (like personal files and e-mail) to speed up searching this content. Disabling this service will slow down the search process to a file by file search. Indexing takes place in the background at a moment the computer is not used, for this reason it is not necessary to disable the service.

35) Windows Time: For automatically synchronizing the time and date. If it is not essential that the shown time is correct, disabling the service is no problem.

36) Windows Update: Automatically detecting, downloading and installing updates for Windows and other programs. If the automatic updates are not desired, disable this service. Note: after disabling this service, it is no longer possible to do a manual update as well.

Other services
It is advised to keep the services which are not mentioned on this page unchanged.

Welcome screen and Fast user switching disabled in Windows Xp by netware

Problem :- After installing XP and it does not give me the option to select from either one of these two options. When you try, You may receive the error: “Client Services for NetWare has disabled the Welcome screen and Fast User Switching”.

Solution :- To restore these features you must uninstall Client Services for NetWare.
Try the following solution
Solution Step 1
1) Open control panal and Open Network Connections
2) Right click on LAN and select Properties. Under General click on’Client Services for Netware’ & then press uninstall
3) Then Reboot Your PC.
You should now be able to go into the user account control from the Control Panel, and change the way users log on/off.
For some reason If you don’t see Client Services for Netware option try this
Follow the above procedure to get to the network properties (of the network you are using currently). If you can’t see any netware entries do the following:
1. Highlight your network, and click install button.
2. Make sure “Client” is highlighted, and click add.
3. Highlight “Client Service for Netware”, click OK
4. Allow your PC to restart.
Now follow the first method instructions again, and hopefully ’Client Services for Netware’ should be there for you to uninstall. If not try Solution 2

Solution 2
1) Go to Start>Run> type Regedit click OK.
2) Now navigate to the following key from left pane
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon
and delete GinaDLL key from right pane
Then Reboot Your PC.
You should now be able to go into the user account control from the Control Panel, and change the way users log on/off.

System freezes at "Welcome to Windows XP setup screen"  during OSRI / REPAIR / PARALLEL Installation

This problem normally occurs on systems that have 2GB or Greater RAM installed. 

Problem:

System freezes at "Welcome to Windows XP setup screen"

Description:

On Dimension 4700/2400 system some times system freezes at Welcome to Windows XP setup screen during OSRI / Repair / Parallel. Most of the times  you may consider the fast tapping of F12/F2 keys by the customer as the cause of the issue.

Solution:

Although fast tapping of F12/F2 keys can be the reason for system freezing at the welcome to setup screen  there is one more option in the BIOS which causes this. This option is - OS Install Mode On/Off. The default setting is OFF for the option and that's what causes the lockup. Try to  perform following steps in such cases:

1)    Shut down the system and release flea power.

2)    Go to the BIOS by tapping F2 / Delete key

3)    In the BIOS, make CD/DVD Drive as the first boot device.

4)    Come back to the main BIOS screen, scroll down and look for OS Install Mode and turn it to ON.

5)    Clear the event log.

6)    Save BIOS settings and restart.

7)    Now Boot from the CD

Look at following link for Dimension 4700/2400 setup options:

Dim 4700 - http://support.dell.com/support/edocs/systems/dim4700/sm/syssetup.htm#wp1052347

Dim 2400 - http://support.dell.com/support/edocs/systems/dim2400/en/sm_en/syssetup.htm#1105422

***** CAUTION *****

Enabling the OS Install mode in the BIOS will restrict the system access to only 256 MB RAM, regardless the amount of RAM installed.  It is imperative that after the operinting system has been installed, that the OS Install Mode be reset to OFF ! If not done, Windows will report & use only 256MB RAM.