Norton SUCKS.
They've come a long way, sure, but now they've seemed to take the line of "if you can't beat em, join em"- getting rid of norton is a major PITA, and the toll it takes on your system performance and footprint wise is unacceptable.
Get Microsoft Security Essentials- it's free, it works awesome, and when used in conjunction with UAC on Windows 7, you're nearly virus proof- anything and everything needs your permission when accessing administrator privs, so unless you are not paying attention, you should be just fine.
Good luck getting your system fixed. After you get through with the Norton run do this: Uninstall Norton, run CCleaner to make sure the symantec info is out of your registry, then download and run MSE in a full system scan to see what Norton left behind.