Getting a virus from limewire is very rare. Ive only even heard of it once but ive never heard of 200+ unauthorized downloads before.

This is what I would do if I were you:
run Windows update then Microsoft Baseline Security Analyzer http://www.microsoft.com/technet/se...s/mbsahome.mspx

Next try using:
-ad-ware http://www.lavasoftusa.com/software/adaware/
-Spybot - Search & Destroy 1.3 http://www.safer-networking.org/en/mirrors/index.html
-Spy Sweeper http://www.webroot.com/wb/downloads/index.php

That only covers hacking and spyware problems im guessing you already have an anti-virus?