XP Pro Upgrade Nightmare

I just upgraded my Toshiba Laptop from XP Home to XP Pro. It originally had the OEM XP Home on it.
After the upgrade I could not get any updates from the microsoft update center so I called Microsoft, paid $35 and they fixed it.
However,

The computer is extremely slow and and CPU usage stays at 100%. Can anyone help me out here?
It it a good computer, I have 1gig of ram, 100 gig harddrive. If you need anything else let me know.

I hope someone can help me!!!!!!

 

First thing you would need to do is find out what processes are running, and then narrow down to the one that is causing the system to run at 100%. If you open Task Manager, it may show what is causing the 100% (System Idle Process shows the amount of CPU not being used).

 

Thanks for the quick response. It turns out that it was the built in mouse pad driver. After a driver update everything seems to be running okay. If anything changes I will just add to this thread.