Help me.. pls

Hello,
i have problem for last 3 years...
the problem is that when i open my computer, my mouse scroll automatically... so i cant read pdf docs, or pages that contains vertical or horizontal scroll bars.. ie the pages will be automatically scrolled..
even i cant touch slider like volume..., dos prompt.. finally i removed my mouse but the problem remains the same..... so pls help me .. i think it is a virus like vbscript.. i used so many good antivirus such as norton,avast,node... but when i used the kaspresky it is showing the ther is some "suspecious" in your svchost.exe process not a virus.... i reinstalled many time the windows xp but the problem not solved...
expect good reply
Muhammed Rafe.P