Sean,
Sounds like you
may have contracted a Virus. See Link below.
To fix the limewire keeps popping up / no taskmanager bug do the following.
I have read that Brut Force Uninstaller might not be fixing this problem anymore, so I will also recommend this.
This is probably one of the best help Forums for Malware I've found. Just another suggestion.
Malware Removal - MajorGeeks Support Forums.
Good Luck!!