I got a virus on my box..

..( backdoor.sdbot) Norton cleaned it all except C:\windows\system32\system32.exe......It keeps telling me that it can't clean this file. So disabled "system restore" , Next Exported my registry, then I booted up in safe mode and deleted the file. My system runs fine but at boot up I get this error message saying that it can not find system32.exe. I was wondering if I searched for system32.exe though the entire registry and remove the entry for system32.exe if that will get rid of the error.
Any thoughts.
The only good thing I is that I am studing for the 70-270!
Thanks!