Slow and locking up

I had a Trojan several years ago and thought it was resolved. But my computer has been eaten up with spy/malware since. Now my computer is so slow and freezes up a lot. I've ran scans, but they never seem to detect anything and my computer is getting worse.

Take a read through this and then start a fresh thread in this forum and post a HJT log, and a brief description of your problem, and somebody will be along as soon as.
Helpers look for posts with zero replies which is why you need to start afresh and why i'll lock this one.