You can clear all locally stored configuration options in a phone by using the Phone Settings menu. When you use the restore to factory default option, all user-defined entries in Network Profiles, Phone Settings, and Call History are erased.
To erase the local configuration, follow these steps:
Step 1 Choose SETTINGS > Phone Settings.
Step 2 Press **2 on the keypad.
The phone briefly displays "Start factory reset now?"
Step 3 Press the Yes softkey. All settings are deleted.
The phone cycles through normal startup procedures.
Or press No to cancel the reset.
Step 4 Press SETTINGS > Network Profiles to reconfigure the network settings for your WLAN.