To clarify the part re: spyware, it sounds like you have spyware and it just happens to be prefetched in the OS like many programs that are run. I don't believe that prefetch is the source of your problem, instead it's the spyware. If you clean the spyware, the "prefetch" part should go away too.
Here's a thread re: spyware removal:
http://www.tfproject.org/tfp/showthr...threadid=48137