A type of PC Access user authorization which resides on your computer's hard drive. You can uninstall a disk tie user authorization with the UAM, but you cannot back it up to tape, move it with DOS or Windows commands, or disturb it with a disk defragmenter (e.g., Norton SpeedDisk) or compression program (e.g., DBLSPACE). Before you run a disk defragmenter, make sure you have set it not to disturb files with system, hidden, read-only attributes. Before you run a disk compression program (which MFM advises against in any case), you must uninstall your disk tie user authorization with the UAM.