I got it working on Windows 7.
You'll need to extract from an XP installation CD or copy them from a running Windows XP installation, 3 files to their own folder that you create on your Windows 7 desktop
Once you have those 3 files in their own folder, run the ntbackup.exe and the program will start.
You'll get an error that "Backup Utility cannot connect to Removable Storage service"
Put a checkmark in the Do not show this message again box and click OK.
The program will start in Wizard mode.
Under "What do you want to do" click "Restore files and settings" and click Next.
A window will open prompting you for the location of your backup file.
I didn't have a .bkf file to work with so I had to stop there but I can verify that the program will
run on Windows 7 Pro x64 using the instructions above.