Acer aspire 3500 laptop.my keyboard and mouse keep freezing. its a software fault. can someone help?

I have reformatted with the back up disk with no success. in safe mode though they do work. can someone help !
Answer
Lol sounds like virus , some viruses modify or patch using asm int chains , that load up ya mouse and stuff. suggest getting avg antispyware 7.5 since its free, and works as nice as comercial, spybot wont do since it removes only low class spyware. codeseeker