I have recently had a trojan on my computer which i was not too happy about but i managed to get rid of it and everything it put on my computer like other viruses, malware and spyware but it has done conciderable damage. It is completely clean of harmful things though as i have used forums for advice on cleaning it and it is spotless

My problem is that everytime i try and shut down my computer, everything freezes and my CPU usage goes up to 100%. I have to to Ctrl+Alt+Delete to load up the task manager and shut it down from there. The application that is taking up all of my CPU usage is "Explorer.exe". Also if i leave my computer on for a certain amount of time (usually over 6 hours) the CPU usage goes up just like when i try and shut the computer down. And this is for no reason. I really don't know what to do. Please Help!!!!

I would suggest a Repair Install if you have a retail CD:

http://michaelstevenstech.com/XPrepairinstall.htm

Or a non-destructive Recovery if your XP is OEM (pre-installed).

explorer.exe is the basic GUI of XP.

If you want to recheck virus issues you might try our Pros:

Please follow the instructions HERE & then post your log in a new thread in the Spyware, Adware, Viruses and HijackThis Logs section.
(Not in this section please).

Please specify what issues you appear to be experiencing along with your log.