TaxCut doesn't create the backup file in a proprietary format. Restoring your tax return files is as easy as copying the files from their backup location to a location that TaxCut can conveniently access.
If you have backed up your tax return files to a disk or other external storage device, simply copy them back to the hard drive of your computer. Make sure you don't overwrite any tax return files that you may already have on the hard drive.
Note: TaxCut saves the data from your federal and state tax return in the same file.