PC problems

[Northy]

I'm having a problem on my home laptop - this is what happened:

Some guy from work sent a document that needed a .net something or other to view it, so I downloaded and installed it last night.

Today it starts going off it's tits. Keys on the keyboard not working, start menu popping up and closing like it's on crack.

I uninstalled the .net crap and re-booted.

Then some keys on the kb started working again, but the start menu is still going off it's tits!

Run a full scan with AVG - found nothing.

Any ideas?

G