Below are the steps to root Android 4.2.2 on the Nexus 7. But before going ahead, the user must note that although the procedure is a tested one, I will not be held responsible for anything that goes wrong. PROCEED AT YOUR OWN RISK!
1. Ensure your tablet is running Android 4.2.2. Check by going into Settings > About Tablet > Android Version. If you are not, click Settings > About Tablet > System Updates > Check For Update.
1. Ensure that you have the Android SDK installed on your computer. If you don't, click on this link: http://www.redmondpie.com/how-to-set...dows-tutorial/
2. Enable USB Debugging mode. Go to Settings > Developer Options > USB Debugging.
3. Backup all your personal information on your device. You can use App Backup & Restore to backup all your apps. Use SMS Backup and Restore to backup messages. You can backup your contacts using Gmail.
4. Make your your Nexus 7 is charged with at least 50% of power.
5. Please disable all the Antivirus programs running on your computer as the may interrupt the rooting process.
How To Root And Install CWM Recovery On Nexus 7 Running On Official Android 4.2.2 JDQ39 Firmware
1. First you need to download Fastboot file here:http://android-roms.googlecode.com/f...boot-win32.zip and extract it to android-sdk-windows\platform-tools directory on your computer.
Note: This folder will be available only if you have installed Android SDK. If this folder is not available then you need to install the Android SDK.
2. Now download ClockworkMod Recovery 188.8.131.52 file here:http://download2.clockworkmod.com/re....3-grouper.img and copy it to android-sdk-windows\platform-tools directory on your computer as well.
3. Now download Superuser here:http://download.chainfire.eu/310/Sup...erSU-v1.04.zip and copy to the root of your internal storage. (Not in any folders.)
4. Now move the backup you created to your computer because your Nexus does not have a removable SD card.
5. Now switch off your tablet and boot into Fastboot Mode.
Boot your device into Fastboot mode by pressing and holding Volume Down+Power buttons together until Fastboot Menu screens turns up.
6. Now go into the android-sdk-windows\platform-tools directory on your computer and Open Command Prompt.
To Open Command Prompt, press and hold Right-Shift button and click in the empty space on the screen and select Open Command Prompt here.
7. Type fastboot oem unlock and follow instructions on the Nexus. Note: This will wipe all your data, last chance to make a backup and move it to your computer!
8. Now type the following command and press enter:
fastboot flash recovery CWM-grouper-recovery.img (If adb cannot find the file, rename it to CWM-grouper-recovery.img)
Once this is done, choose RECOVERY from the Fastboot Menu and enter into Recovery Mode.
9. In advanced options, select mount SD card and copy the UPDATE-SuperSU-v1.04.zip from the backup on the computer to the Nexus.
10. Boot to Recovery mode and select Flash zip from SD card. Select Choose zip from sdcard.
Note: In the Recovery Mode, use Volume keys to navigate and Power button to select.
11. Now navigate to the UPDATE-SuperSU-v1.04.zip that you copied to your SD card in step 3.
The installation will start and will take some time to complete.
Now in the recovery mode, select +++Go back+++ and then reboot your device by selecting Reboot system now.
12. Now move the backup on your computer back to your Nexus.
That's it! You have successfully rooted your Nexus 7 and managed to install ClockworkMod Recovery on it! You can now install custom roms and kernels.
Don't forget to hit thanks!