vinouspleasure,

What about spyware? Check the system with ad-aware or spybot search and destroy to see if the system has spyware that is taking up system resources.

thanks...good suggestion but I use spybot s&d already.

Can you use the WXP's restore program?  Go as far back as possible. 

Try removing all devices from the MB except for the RAM, HD, keyboard, and mouse.  Reseat video card, too.  Still seeing 100% CPU load?  Did you recently load new driver?  You may want to go to Administrative Tools\Services and look for items that shouldn't auto start.  Use this list as a guide:

automatic updates...D
COM+ event system...A
Error reporting...D
Event log...A
HID input service...A
IMAPI CD burning...D
Indexing service...D
Logical disk Manager...A
Messenger...D
Network Connections...A
Network location awareness...D
Norton Antivirus...A (SystemWorks 2002 only)
Plug and Play...A
Print spooler...A
Protected storage...A
Remote access auto connection manager...A
Remote access connection manager...A
Remote procedure call...A
Remote registry...D
ScriptBlocking Service...A (Norton SystemWorks 2002 only)
Security accounts manager...A
Shell hardware...A
Speed Disk service...M (Norton SystemWorks 2002 only)
SSDP discovery service...D
System event notification...A (best?) or D
Task scheduler...A or D
Telephony...A
Terminal services...D
TrueVector...A (ZoneAlarm Pro)
Universal plug and play device host...D
Windows audio...A
Windows image acquisition...M (go to properties\logon\disable profile 1)? but will get com alert
Windows management instrumentation...A
WIndows management instrumentation driver extensions...M or A
Windows time...D
Workstation...A

F.