I installed some large programs today, and also cleared off a bunch of old ones using the "add/remove software" thing. This all went fine.

I restart my computer, and now my CPU usage is all over the place. Upon startup, with nothing running, it jumps from 2% to ~45% then to 100% all withing two seconds and then endlessly repeats this.

I've run AdAware, the newest free AVG, and the free online Pandascan with no luck. Please help me

what the heck is Pandascan?? whatever it is you probably shouldnt rely on it. Ad-aware is good but it wont find everything. Use that plus Spybot-Search and Destroy, and you should be covered. if that doesn't solve the problem make sure has nothing to with windows processes or the paging file...

Your problem doesnt sound like a virus or spyware. Sounds to me like one of the programs you had uninstalled has done a poor job of uninstalling! Often in poorly coded programs, the uninstall wont remove the program completly, leaving traces of it scattered through-out your pc to clog up space and slow your computer down. I reccommend going to www.freeware.com and downloading "Startup Control Panel" It will install to the control panel. So to use it, go to start button-->control panel-->then open the "startup" icon. If you dont see the icon, click "Switch to classic view" Then disable everything and reboot. This way your computer will only load the system and no other software. You can pick and choose what loads at startup. However, at first I would disable everything and reboot, to make sure it solves the problem. Like I said, its likly that a program didnt completly remove itself and is tring to load a piece of the program upon startup.