What I would do with the old one is... If you have the recovery CD that came with the computer, I would just put that in and let it wipe it clean, then reinstall everything and go in and delete whatever I didn't want. That would replace the missing files so that you could do that.

I am thinking about doing that to my house pc because it is running so slow and no matter what I do, it don't get any faster. Something is bogging it down and I can't figure out what so I can get rid of it.