Have you read Windows 7 Help & Support regarding backups?
Open Backup & Restore and click the blue (?) near the upper right.
Have you tried to simply browse to your backup file and double click it to see if it will open a backup and restore window? How about right click and "open with" (if available) and browse to windows backup & restore?
Can't give specific's as i've never used it, but it does say that you should be able to restore files from vista within 7.
good luck. Edit/Added:
Here's a tutorial on this forum for restoring files, hope it helps.
Restore Backup User and System Files