WIndows XP Problem

Hello,

BT IT installed Macfee on my PC a few days ago and it was doing a scan and it found c.windows32 or something like that, it showed as a virus but I believe my windows was not genuine becasue lately I was getting pop up informing me of this. Anyway, when I start my pc I have a login for windows on my desktop, and I have my wallpaper but no icons, no start button and no task bar. When I login in, it logs me back out again and I am unable to do anything at all. I have tried the F8 button etc but no use. I have tried opening in safe mode and the other modes but all in vain. I don't have a windows cd and I had paid a lot when I had the computer built. I have college work and photos and a lot of other things which I can't afford to lose. I would appreciate if someone can give me advice, taking into account that I am no expert with the computer.