Nexus devices are the first to receive the Android 4.2.2 Jellybean from Google. The update is a fresh release from Google and it features new tweaks for Quick Settings, new download notifications, new sounds, performance improvements, and increase in battery life.
For Google Nexus 7 users, if the OTA or Over-the-Air update did not work on your device, there are two other ways to put the official update inside your Nexus 7. Qbking77.com made a demonstration about the update.
This version is for Non-rooted Stock ROM Google Nexus 7.
2. Go to the device Settings and then to the About Tablet to check your firmware and build number.
3. Tap the Build Number a couple times until it shows "You are now a developer."
4. Go back to the Settings and go to the Developer Options, turn it on. After that, check the USB Debugging option.
5. Once you have the tools ready and the device, copy the zip file then go to this path: Android-sdk folder > platform tools >. Paste it in that location.
6. Inside the Platform Tools where you pasted the zip file, right-click and choose "Open command window here". A new command window will appear.
7. Plug the Google Nexus 7. Type "adb devices" in the command window and it will list all devices attached to the computer, ensuring that it is identified and detected. Then type "adb reboot recovery".
8. The device will reboot and it displays "no command". Press the Power and the Volume Keys then the Android System Recovery menus will be displayed.
9. Go back to the Platform Tools folder, and copy the only the "label" of the zip file, not the zip file itself.
10. Then go back to the device and press volume buttons to navigate the menu. Choose "Apply update from ADB" by pressing the power button. A text will be displayed: "Now send the package you want to apply to the device with 'adb sideload '...
11. Back to the command prompt, type adb sideload and then paste the label you have copied before. To paste it, right-click on the top part of command windows and select edit > paste. The text would look like, "adb sideload (filename).zip". If there is no .zip at the end, simply add one. Then hit enter.
12. After update, choose "reboot system now" in the device by pressing the power button. Wait for the complete boot up and unplug the device.
13. Double check the device by going to this path, Settings > About Tablet. Android 4.2.2 version should be displayed making the device fully updated.
In this process, there is no need for any wiping data files in the device.