Unformat a floppy disk

Unformat a floppy disk,

A manager in our office accidentally quick formatted a 3.5″ floppy disk using windows 98. I have had no success unformating the disk with the dos 6.22 unformat command. I think the problem there is that it was formatted with a different version of dos. We have also tried McAfee utilities, but it also uses a dos unformat command that does not recognize windows 98.

Does anyone have a good idea on how to unformat this disk?

Thank You
Brian