If you originally had PC Tool's Spyware Doctor 2010 (with their A/V included) it's best to either keep Norton 360, or Spyware Doctor. Not both. Have a look at PC Tool's Spyware Doctor Forum, where the same question has been asked, in regard to Norton 360 and other A/V software. You'll see where it's not recommended.
Best of luck..
I have norton 360 3.0 installed and I just recently installed pc tools spyware dr. 2010. Since my computer will not fully load. I uninstalled spyware dr and it is fine. Is there anyway to be able to have both programs together with no conflicts?