Oh-oh, I have experience with this one, I had it about a month ago. Go grab the tool from symantec with the link provided by Maverick, and follow the instructions carefully. Be sure that when you try to reinstall your anti virus, that you are NOT connected to the internet. Im pretty sure the instructions require you to download the fix, disconnect from the internet, turn off file restore (which sometimes klez infects as well), boot into safe mode, run the fix, boot into regular mode, re-install norton, turn file restrore back on. I hope this helps.