Reset Nexus One to Factory Settings, sometimes your Nexus One may freezes or doesn’t respond, if this happening continuously than you need to reset your phone to the factory settings called hard reset. To hard reset Google Nexus One mobile phone you need to do the following steps.
Before hard resetting your Google Nexus One make sure you have backup your all date including your emails, contacts, pictures, music, etc.
Reset Nexus One to Factory Settings
Tap on Home icon, tap on Menu icon and then Settings
Tap on Privacy and then Factory data reset
Read the text carefully on your mobile b/c hard reset will erase your all data on Google Nexus One.
tap on Reset phone button and then Erase everthing button