Laptop Keyboard Automatically Type Slash Bars

Hello there, My keyboard automatically types \\\ (slash bar) on the text box or text area (everywhere I write). When I tried to delete them… it replaces with pppp.It even sometimes doesn’t allow to delete \\\ or ppp etc.
I already have Macfee. I thought it should be some virus or malware and so installed some anti-virus/ani-malware tools like Microsoft onecare and Malware bytes. Each of these scans found some virus, I got them removed. I remember that Malware bytes has detected trojan hiloti and onecare has detected some 14 affected items and 7 issues.
Its very difficult to write anything on the text area or test box or anywhere. This happens everytime every day. But, at sometimes my system works normally and keyboard works normal but it last for 1 or 2 days (sometimes 1 week) only. And it again appears the same problem after few days. Someone suggested me that its a problem with Battery. I now have given direct power supply to my laptop but it gives the same problem.

I have restored my Windows to the factory model, however I am still facing the issue.Now, I didn’t install any sofware other the software Microsoft provided, but the problem still exists.My model is Sony Vio VGN-C2S. Its intel Core 2 Duo and 1GM RAm (Upgraded to 2GB RAM).

Could you please suggest me some best approach to get this removed.