Update 2020: The steps in the attachment are still accurate for current versions of GV-DVR/NVR/VMS. The PC UI may differ slightly but steps remain the same.
If there is no way to retrieve password for any Supervisor account, you may run PassUninstall.exe to completely reset the password database.
Refer to Password Removal Guide as attached below for step-by-step instruction to reset password database.
Note: this document uses GVCombo and GV800 as examples. Substitute these for whatever software you use (GV-VMS, GV-NVR, GV1480, GV600, etc)
Whether you may run PassUninstall.exe successfully or not will depend on if you had previously granted the privilege to do so during the initial setup. If you do not have enough privilege to run PassUninstall.exe, you will need to reformat C:/ and reinstall Windows. Since the password database is encrypted under Windows, simply uninstalling GeoVision software will not remove the password database.