This depends on the version of Copy Protection used. The Copy Protection on Digidesign software released prior to 3/97 used invisible 'key" files which could be backed up and restored. Formatting a drive without backing up or deauthorizing would result in the key being lost.With software released after 3/97 (starting with Pro Tools 4.0), formatting the hard disk should have no effect on existing authorizations. The only time the user should have to 'verify' their authorization is if they perform a device level format and they haven't backed up their hard disk. If this happens, the user should be prompted to insert their key diskette when launching the app. If they insert the key diskette that they originally used to authorize their hard disk, the Copy Protection will recognize it and automatically restore their authorization without affecting their hard disk install count.