There are several variants of W32.Nimda in general circulation. Two of the most common are:
* W32.Nimda.A@mm
* W32.Nimda.E@mm

Symantec Security Response has created separate removal tools for both of these threats. The tools are not interchangeable. Before you can use a removal tool, you must know which variant has infected the computer. W32.Nimda.A@mm Removal Tool will not remove infections of W32.Nimda.E@mm.

You must have administrative rights to run this tool on Windows NT, Windows 2000, or Windows XP.

If you are running the tool run on a Microsoft Exchange 2000 server, you must stop the Microsoft Exchange service so that the tool does not try to scan the virtual M drive.

The fixtool does not run on a Novell server. Infected files that are on a Novell server cannot be repaired. The Novell server itself will not be infected, but any files that are located on the server can store the virus code. On Novell volumes, you must delete any files that are detected as infected, and restore them from a clean backup.