Quick search and i found this...
- Select Start - Run.
- At the Open prompt enter: mmc
- Click OK
- Select File - Add/Remove Snap-in...
- Click Add...
- Select Microsoft SQL Enterprise Manager
- Click Add, then Close
- Click Ok to return to the mmc.
- Select File - Save As...
- Delete or rename the original (offending) file out the way.
- Save the new msc file as C:\Program Files\Microsoft SQL Server\80\Tools\BINN\SQL Server Enterprise Manager.MSC
Here is the original page if your interested where it came from http://geekswithblogs.net/timh/archive/2005/08/09/49716.aspx