Your computer's probably infected.

Try the various fixes in the threads below...there are different fixes to try because there seem to have been a few variations of this thing over time.

2 probs (LW keeps restarting & can't access options)
Starts on its own/ options folder won't open (possible fix)
installation aborts
WARNING: Viruses on network you should be aware of!

Make sure to give AVG Free a try...it's been pretty good at finding viruses which other AVs miss. Make sure to update AVG before scanning your computer. There's a link for download in a couple of the threads above.

If you're still stuck, please go to one of these sites - they're specialists in malware removal & can help you.
Spyware Warrior :: Index

Malware Removal - MajorGeeks Support Forums

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