Hard Drive Failure or Virus?

My problem first started out with Vista randomly freezing for sometimes 20-30 seconds (but I could still move the mouse), and then it would go back to normal. Other times it would freeze indefinitely, and then the computer would restart on its own.

Now the problems are getting more severe. My entire section of my start menu with my favorite/most used programs is now blank. I had the run command enabled and it now its disabled and wont re-enable. My user icon on the start menu randomly shows as a question mark, turns into my icon, and then goes back to being a question mark. ClearType turned itself off and I had to go and turn it back on myself. I loaded into my Zune software and it showed me the start screen, as if it was being loaded for the first time.

Any advice on this, sound like a virus or a failing hard drive? I ran the basic WD Diagnostics and everything seemed to be fine. I really don't want to move everything over to my other HD but I will if I have to. Thanks!

I think that you may have more than one problem, although a failing disk would account for some of the problems it would not account for all of them and the disk diagnostic utility has ruled it out. A more likely common fault is a failing power supply.