User in my office is infected (again, 4th time in the last 4 months). Had to remove Spyb ot cause it kept popping up with registry changes, you click "deny change" and it just pops right back up. McAfee also kept reporting a "BackDoor.BAC" virus (which according to their site their program has been able to detect and remove since 2003 but it won't let me Clean, Move, or Delete the infected files). We don't have any spyware programs here, can't get the firm to buy them yet, so I need free tools or manual instructions to remove whatever is on here. I've tried removing the files in question t