I'm no guru but I'll quote THE Geek from this post:
http://www.flyaceshigh.com/forums/showthread.php?s=&threadid=71591GENERAL CPU UTILIZATION
Windows, by default, has several processes which run in background, that can cause odd problems with online gaming as well as security issues.
For Windows 2000 and XP users:
Go to your Control Panel and doule click the "Administrative Tools" ICON. Then double-click the "Services" ICON.
This will show you a list of processes Windows will run or start at boot time. Some will show as "Running". To alter the state of any of the listed processes, simply right-click on it, and select "Properties" from the pop-up menu.
The processes you can safely "Disable" are as follows:
Automatic Updates (this is one nasty program)
Background Intelligent Transfer Service
Fax Service (NOTE: unless you are using your computer to send/receive FAXES)
Internet Connection Sharing (NOTE: unless you use your computer so that other computers access the Internet through it)
NetMeeting Remote Desktop Sharing
Messenger
Print Spooler (unless you have a printer connected)
Remote Registry Service
Routing and Remote Access (unless your computer is also acting as a router for the LAN)
Smart Card
Smart Card Helper
Task Scheduler (unless you have your computer automatically run programs for you...not recommended to leave enabled)
Telephony (NOTE: XP and Windows 2000 Service Pack 3 or later users may not be able to disable this without it disabling your Internet connection)
Telnet (unless you want to be able to telnet to your computer from a remote location......not recommended to leave enabled)
Uninterruptible Power Supply (unless you have a Windows compliant UPS system)
All others are at your discretion, but take care. Windows will allow you to shut off services that can keep your computer from booting. The ones you must not touch have RPC in the name.
A well tuned Windows 2000/XP system should only have about 19 to 21 background processes running, as reported in the Windows Task Manager (Ctrl-Alt-Del, under the "Processes" tab)