How come my computer is considerably slower than normal?

by on January 1, 2013

Q: My pc is a bit slower than usual. Some of my files as “hidden” but I can’t unhide it. Some random files appear on my C:// which were never there and I (the¬†administrator¬† does not even have access to it. Some changes have been made to my settings. And the strange thing is, that I have never seen my CPU usage monitor over 70%, but now, it is constant on 100%, although I have no applications running. What can be the problem? Specs: 2.6ghz processor, 8gig ram, win7. . .