Ditch Norton. It's awful. Has been for over a decade.
Boot into an Ubuntu LiveCD. Destroy the contents of C:\Users\Username\Local Settings\Temp (replace 'C:\Users' with 'C:\Documents and Settings' if using XP). Be aware, of course, that it won't say 'C:\' - the path leading to the Windows partition will be different (/media/<UUID>, to be specific), but as long as you know you're navigating in the Windows partition, clear out that Temp cache.
When you're done, boot back into Windows.
Use AVG or Avast! if it's really of concern. For brownie points, Avast! has a Linux version which can be used to scan/clean up the Windows partition. It uses the same definitions as the Windows version, but A) uses a much less resource-hungry interface and B) since it's not running on Windows, it stops the malware from interfering with the scan/removal.
Use RKUnhooker to see if you've been infected by a rootkit, and if it finds anything, tell it to unhook those things, and then run ComboFix to remove them.
Run scans with Spybot and Malwarebytes. Repeat as many times as necessary until you get no hits. Tell Spybot to Immunize the computer (the immunization feature is actually the important reason to keep Spybot around, even if you never run scans with it again).
Run CCleaner to clear up the basic stuff, then run the Registry cleaner over and over again until it stops finding things.
Use Lynx to look at porn, you pervert.