I don't see SP2 mentioned in your sidebar, just XP. SP2 included a fix for this very problem, aswell as a host of other fixes. You can get a free download of SP2 from Microsoft, or in certain countries they'll send you a free SP2 update on CD.
Alternatively, I do know that without SP2, the Indexing Service can cause 100% CPU usage, so disabling that may help. Make sure you fully disable it:
1. In My Computer, right-click C: drive, choose 'Properties'
2. Under the 'General' tab, at bottom, UNtick "Allow indexing service...etc...."
3. Click 'OK'
4. Repeat for all hard disks on your system.
5. Now click 'Start->Run, and type SERVICES.MSC, and press 'OK'
6. Scroll down to 'Indexing Service' and double-click it.
7. Beside 'Service Status' (at bottom of dialog box) if it says "Started", click 'Stop' button.
8. Now beside 'Startup Type' (middle of dialog box) change it to "Disabled"
9. Click 'OK' ---- Phew! --- your done!
Hope that helps.
NB.-- the list of fixes and security in SP2 is here: http://support.microsoft.com/kb/811113
There's only one fix for 100% CPU usage listed (as far as I can see), and that's concerning the one I've referred to above. The fix is for people who don't want to turn off the indexing service.
Edited by pip22, 30 October 2007 - 02:04 PM.