my computer

Right now i am using my dad's computer because my computer is so messed up. We think it's a virus. It is going slower than ever, the background won't change to my preferences and when my dad put google as my home page, and he went back to it, t went back to MSN. So it is screwed up. And that was just now. When that happened he said we're going to have to re-do the whole computer from scratch. So that is just what might have to happen. Right now he is doing a full scan to see if there are any problems.