NOTE: In the case of VPN capable phones make sure that the phone is behind an ASA or a Managed Circuit before performing a factory reset. Failure to do so can result in the phone losing it's VPN capabilities entirely.
Reset via Software
Step 1 From the Administrator Settings menu, (unless a password has been set)
Step 2 Choose Reset Settings > All Settings.
Reset via Keypad
Step 1 While powering up the phone, press and hold #.
Step 2 When the light on the Mute button and handset light strip turns off and all other lights (Line button, Headset button, Speakerphone button and Select button) stay green, press 123456789*0# in sequence.
When you press 1, the lights on the line buttons turn red. The light on the Select button flashes when a button is pressed.
If you press the buttons out of sequence, the lights on the line button, headset button, speakerphone button, and Select button turn green. You need to start over and press 123456789*0# in sequence again.
After you press these buttons, the phone goes through the factory reset process.
Do not power down the phone until it completes the factory reset process, and the main screen appears.