[icanspelltree]

I can't seem to launch Internet explorer, or regular windows explorer, i am currently having to use task manager to launch any programs. It seems as though everything but these two programs will run. I have tried typing in, and browsing to the different programs using the "new task" command in task manager, but that also doesn't work.
I can't seem to target the problem. I have been trying to find out if it's a worm or virus by scanning my computer with McAffe, ad-aware, and another program which i forgot it's name.
I recently updated my Firefox browser to the newest version (2.0) and soon after my computer started this.
When I start my computer it sometimes flashes the start bar at the bottom of the screen, but it quickly disappears. Sometimes when I try to launch explorer by using the task manager it will flash, but then also goes away very quickly.
This is really starting to get to me. I don't have a back up copy of my OS, which also sucks, so I'm trying to see if anybody can give me a hand. Have any ideas?