A few Great XP tips!

Edit sysoc.inf to list all software
To show all software that can be removed from your computer (including protected Windows services), you can manually edit (using notepad for example) the sysoc.inf file located in Windows\inf\. Just remove the word hide next to the software pack.
*Note* - use this at your own risk. Removing critical components of the system will make Windows instable.

Disable system services for maximum performance
There are system services that you can disable to free up the system’s load. To access the interface that permits you to make changes to system’s services, type services.msc and the command prompt.
This is a list of services that are *usually* useless and can be safely disabled.
Alerter
Application Layer Gateway Service,
Application Management
Automatic Updates
Background Intelligent Transfer
Clipbook
Distributed Link Tracking Client
Distributed Transaction Coordinater
Error Reporting Service
Fast User Switching Compatibility
IMAPI CD-Burning
Indexing Service
IPSEC Services
Messenger
Net Logon
Net Meeting
Remote Desktop Sharing
Network DDE
Network DDE DSDM
Portable Media Serial Number
Remote Desktop Help Session Manager
Remote Registry
Secondary Logon
Smartcard
SSDP Discovery Service
Uninterruptible Power Supply
Universal Plug and Play Device Host
Upload Manager
Webclient
Wireless Zero Configuration
WMI Performance Adaptor

*NOTE*: Make sure you don’t need them since some applications you’re using could depend on them. If you make any application to fail by disabling any of the services, go back and enable it again.

Repair Windows XP by using the XP installation CD
If your system failes to start due to an error related to missing HAL.DLL, invalid Boot.ini or any other critical system boot files you can repair this by using the XP installation CD. Simply boot from your XP Setup CD and enter the Recovery Console. Then run “attrib -H -R -S” on the C:\Boot.ini file and delete it. Run “Bootcfg /Rebuild” and then Fixboot.

Use systeminfo.exe to see System Information
You can use the systeminfo.exe command in the command prompt to see System Information, including all Windows updates and hotfixes.

Edit accounts in the command prompt
You can edit accounts by running “control userpasswords2″ at the command prompt.

These websites have lots of Windows XP tips and tricks including Performance enhancement, Networking, Internet, Repairing, Startup/Shutdown etc.
http://www.onecomputerguy.com/windowsxp_tips.htm
http://windowsxp.mvps.org/Tips_Page.htm
http://freepctech.com/pc/xp/xpindex.shtml
http://www.tweakxp.com/
http://www.theeldergeek.com/

http://www.blackviper.com/