Did the 100% CPU usage occur before or after you started scanning? Most scanners usually take as much CPU usage as they can, to be as fast as possible. I don't think deleting Uninstall files would cause your problem to go away.
Have tried finding out what's causing your CPU usage to go to 100%? If not, press Ctrl+Alt+Del to bring up your Task Manager. Click on the Processes tab, and you'll see a list of whatever's running, with how much they're using up under the CPU column. Hope this helps!