<< aloha guys and girls, my norton 2002 a/v detected backorifice.trojan sitting in c:\windows\system32. the file is called umgr32.exe, i'm on winXP so i dont thinkit can do anything (can it?) >>
Can it do anything??? It shouldn't be able to, if you have a properly configured firewall in place. Then again if the computer was set up properly, the trojan should have never been placed on the system to begin with. If you have aquired a trojan I would strongly encourage you to take n0c's first post as advice instead of removing the trojan. God only knows what else may be lurking in the abyss of your hard drive.
Next time around make sure your virus definitions are current and set your AV protection to scan files when "Run or Opened" and "Created or Downloaded". This way you'll catch it before it finds a home on your hard drive.