I just reinstalled Windows XP on one of my hard drives (it was overtaken by a virus or something), and everything works fine (much faster, too), but when I scroll down or up a webpage in Internet Explorer or Firefox a line goes down or up my screen (in the direction that I'm scrolling and like a transition); plus, scrolling action is a little slow.

What's up with that? Will it eventually go away?

I restarted my computer once, by the way.