A couple years ago I switched from NT to Win2k, because spyware bundled with BearShare hosed my system. For the record, Win2k doesn’t protect against spyware, but I’m loathe to upgrade a working system. For the other record, I paid $10 for LimeWire and it was well worth it.
Since then, I’ve found a couple good programs to fight this. The first was Ad Aware. It’s good, but didn’t detect a recent problem. I found out that Pest Patrol often finds spyware that other programs miss. They offer a free scan of your system, and offer detailed instructions on how to rid the menace. While the instructions are clear, they often have many steps, and you’ll probably buy the thing to make your life easier.
Unfortunately, it wasn’t that easy for me. After many attempted removals (all requiring reboots), I was getting nowhere. The asshats who write spyware have it start up immediately, and the asshats who wrote Windows lock all running programs so they can’t be deleted (this is one of the reasons why it requires so many reboots). If you run into this problem, you have to find the offending file and remove read and execute permissions (through Properties->Security). Leave the write permission on, because you need it to delete it.
I told Pest Patrol of this problem, but never got a response. Granted, I can have a bit of a snarky attitude when frustrated, but if I followed Lincoln’s 24 hour rule for poison pen letters, I’d never send any.