Don't get scared. This is fixable even if this is possibly due to a virus. This malware has been identified as Sdbot.worm.gen, Worm.Win32.VB.an, the "AN Worm", sometimes called the "Zodiak Worm"

You don't say what operating systen you use so I'm just going to guess Windows XP

First try these:

1. Go to Tools>Options>Advanced>System Startup & untick option & press apply.

2. Go to Tools>Options>System Tray make sure Shutdown immediately is checked.

If that doesn't work then First try to open your taskmanager (Ctrl+Alt+Del). If that won't open then it's probably that worm. Try going to this link first and try the easy fix:

http://www.gnutellaforums.com/showpo...&postcount=141

If that doesn't work then go to this link:

http://www.gnutellaforums.com/showth...threadid=39612