My screen keeps scrolling up and down by itself..help!!?

I have avast! installed and it doesn't detect any virus..my OS is vista ultimate..Sometimes this problem is not there..but sometimes it comes all of a sudden..what should i do?

My screen keeps scrolling up and down by itself..help!!?microsoft

This could be a problem with your mouse or even your keyboard if you have a scorller on it. Try using a different mouse and see if that helps. Also try using a different browser such as Mozilla Firefox to see if the problem lies there.

My screen keeps scrolling up and down by itself..help!!?norton ghost

Try a different mouse and see if that helps.