You should scan your computer with a good, updated AV program. Check out the thread below for links to online scans & more info about the virus. Check out the fix for LW popping up!!
* WARNING: Viruses on network you should be aware of! *

Also more fixes in the threads below.
2 probs (LW keeps restarting & can't access options)
Starts on its own/ options folder won't open (possible fix)
installation aborts

If that doesn't help, try AVG Free AV & see whether it finds any nasties.
AVG free
Make sure to update AVG before you scan your computer.

Always make sure that you're using a good AV program. Keep it updated & use it to scan EVERY file that you download, BEFORE you open the file.