The following tutorial will teach Nexus 7 users, who installed the Ubuntu Linux operating system on their tablet, how to re-install Android and remove Ubuntu from Nexus 7.This guide was designed as a continuation of our previous tutorial, about how to install Ubuntu on a Nexus 7 tablet, offering users a way to return to the stock Android OS for this powerful tablet from Google and ASUS.
We remind everyone that Ubuntu for Nexus 7 was officially announced by Mark Shuttleworth in October 2012, and it will see an official release in April 2013, accompanying the highly anticipated Ubuntu 13.04 (Raring Ringtail) operating system.
To begin, you will need to have a healthy and running Nexus 7 tablet (8GB, 16GB or 32GB) with Ubuntu OS installed on it, the Android SDK, a standard micro USB cable (the one that came with the Nexus 7 tablet).
WARNING: This step will ERASE ALL THE DATA ON YOUR TABLET. Make sure you've correctly backed up your device before proceeding. You have been warned!
Step 1 – Downloading Android for Nexus 7
Depending on the Nexus 7 model you have, you'll need to download the respective Android image for your device. There are only two models, one with Wi-Fi and another one with GSM/HSPA+. However, for the Wi-Fi model, Google provides both Android 4.1.2 and Android 4.2.1 images, so it's your choice to select the one you want to install.
Just open this page: https://developers.google.com/android/nexus/images#nakasi in a web browser and download the desired Android archive for your Nexus 7 model. Place the archive on your home directory.
Step 2 – Installing Android on Nexus 7
After downloading the above archive, paste the following commands in a terminal to uncompress it (one by one, hitting Enter after each one):
tar zxvf nakasi-jro03d-factory-e102ba72.tgz
Then, connect your Nexus 7 via the USB cable, disconnecting any other mobile device, and run the following commands in the terminal (one by one, hitting Enter after each one):
Enter your password when asked. You may get the following warnings, which you can ignore. The restoration process will continue anyway...
archive does not contain 'boot.sig'
archive does not contain 'recovery.sig'
archive does not contain 'system.sig'
Step 3 – Locking the Nexus 7 bootloader
Once the Android image has been restored on your Nexus 7 device, you can lock it again. Go to the extracted Android SDK directory with the "cd" command and enter the sdk/platform-tools folder. Reboot the device into fastboot mode with the following command...
sudo adb reboot bootloader
...and lock the Nexus 7 bootloader with the following command...
sudo fastboot oem lock
That's it! You Nexus 7 tablet is just like it was when you bought it. If you encounter issues with the tutorial, do not hesitate to comment below.