Hello lbb87,
My first guess would be a rootkit my second guess would be HDD problems
First the rootkit please download extract it to your root like this:
C:\rkr\RootkitRevealer.exe
Close all other programs, windows and disable your screen saver before you start RootkitRevealer.
While RootkitRevealer is running, you shouldn't do anything at all with the PC.
Put down the mouse, back away slowly, and let the program do its work.
Start RootkitRevealer.exe and press the Scan button.
It will take some time to finish an hour is common so just wait it out.
Once the scanning is finished RootkitRevealer will create a log, please copy the contents of that log into your reply.
HDD problems, first run a dskchk on the drive and then go to the manufacture web site and download their hard drive diagnostic tool and run it on the HDD.



