May i add to that, and recommend Sandboxie

Its similar to a virtual machine, in that it provides a barrier between your actual OS, and the one your using, but imo is more convienient, its free, but has a nag screen after a while if you don't pay to register. Still works, though theres a small amount of options missing (nothing major)

But, yeah, like Sensei said, you pretty much voided my next module (computer security)