First check the build number (Settings \ About Phone) and check the build number out which needs to be ETE27.
- Download the 44.4mb update file from Google
(filename: signed-passion-FRF50-from-ERE27.1e519a24.zip) - Rename the file to update.zip
- Copy to the root of the SD card as shown

- Turn the Nexus One off

- Hold down the trackball button and turn on the Nexus One

- Scroll down using the “volume down” button to the recovery option and press the “power” button to select.

- The phone will reboot and allow you to select the firmware to upgrade.

- Scroll down using the trackball and press it to select.



- The firmware upgrade will begin immediately, allow 5 minutes for the flashing stage.


- After the firmware is flashed the Nexus One will reboot.



- Startup shows the upgrade was successful.


Automatic Updating of Applications

New Car Screens

New Car Screens

Tethering and Portable Hotspot