Either go through Google for a fix or search the McAfee or Symantec "knowledge bases" for a fix. Quite often they will have removal tools for trojans that deeply embed themselves in your system. The fix might require editing the registry. Do not be afraid to do this even though everyone will give you dire warnings about editing the registry. It's not difficult and most of the fixes posted on RELIABLE websites will walk you through the process step by step. It's a pain, but we've all been through it at one time or another.