For the last 2 weeks, my PC has become slow as molasses and locks up frequently. When I check Windows Task Manager, it always says CPU usage is at least 60% and it often spikes up to 100%. I ran a virus scan and no viruses were detected. I also ran Ad-aware, and it did detect and remove several items. But that has not helped. I have Windows Vista and I use Google chrome as my web browser. Does anyone have any ideas as to what could be causing this? I've done some Google searches and have not come up with anything of value.