Sometimes when you get a used Polycom phone to save a few bucks you need to reset it to the factory defaults.   You can try to format the phone to see if that helps clear out any old settings.

1. Press the phone’s Menu button.
2. Select Settings.
3. Select Advanced.
4. Type in the password 456 and press Enter.
5. Select Admin Settings.
6. Select Reset to Default.
7. Select Format File System

That will typically do what needs to be done.  If you are still stuck, please contact us and we will try and help you get the phone running.