Unrecognized Media

Anybody ever seen this when trying to restore a Win2K backup file?

“The backup file is unusable. You must erase it, or choose another file”

I’ve been looking for a possible piece of software that will allow me to restore at least some of the data I have in a seemingly useless 4 gig backup file.

Any help would be more than I’m getting from MicroSoft’s web site.