Did you think to search the forums for a similar problem before posting? I'm sure this has been answered close to a thousand times before.
LimeWire continually Popping up & also Opening at System Startup (click on link) which is a
Sticky at the top of this forum section. Remember seeing this?
http://www.gnutellaforums.com/showthread.php?t=35986 If not, do you remember reading the forum rules at the same time you signed up to the forums?
Forum Rules (click here)