I came across an article today at Android Police talking about manually installing Android 4.2:
It listed 4 steps:
Step 1: Download the Android 4.2 zip from Google
Step 2: Boot the Nexus 7 into recovery mode
Step 3: Connect the Nexus 7 to your computer via usb cable, download the Android SDK or the adb/fastboot tools, run “adb sideload” on the zip file
Step 4: Reboot & enjoy
I thought “Great, 4 steps, this should be quick and easy” but in reality, it wasn’t exactly that simple. Here are the steps as I did them:
Step 1: Download the Android 4.2 zip from Google:
I saved mine to C:\temp
Step 2: Boot the Nexus 7 into recovery mode:
Hold the volume down button while it’s booting up
Select “Recovery” using the volume buttons to navigate and power button to select
Press the volume up and power buttons at the same time to get to the system recovery menu
Select “apply update from adb”
Step 3: Do a bunch of crazy bullshit:
Connect the Nexus 7 to your computer with a USB cable.
If your Nexus isn’t detected, it’s because it’s running in recovery mode and has a different Hardware ID and you’ll get a device not found message when you try to run adb. The fix is to download the latest Android SDK, download the usb drivers, modify an inf file and update the Nexus 7 drivers on your computer.
Download USB Drivers
Download the Android SDK from: http://developer.android.com/sdk/index.html, unzip it and run the android.bat file in the adt-bundle-<platform>\sdk\tools folder, which will launch the Android SDK Manager. From the SDK Manager, install Google USB Driver in the Extras section.
Navigate to adt-bundle-<platform>\sdk\google\usb_driver and add the following line to android_winusb.inf file in the “[Google.NTamd64]” section:
%CompositeAdbInterface% = USB_Install, USB\VID_18D1&PID_D001
Unless you’re running a 32 bit version of Windows, then add it to the section: “[Google.NTx86]”
Additional details are here: http://blog.dantup.com/2012/10/fixing-adb-device-not-found-with-nexus-7-in-recovery-mode
Update USB Drivers
Go to the device manager in your computer, locate the Nexus 7, update the driver using the path above.
A rant about the Android Police article: it originally listed a link to adb/fastboot tools that were outdated and couldn’t run the sideload option; that part of the article was silently edited out later in the day. That’s some 1984 shit right there.
A note on the last step in “step 3:” You can’t just run adb and hope it will work. You’ll need to add the path to adb to the System Environment Variable “Path” so the system knows where the file is: C:\<wherever-you-saved-it>\adt-bundle-<platform>\sdk\platform-tools\
Load the Android 4.2 zip
Once you’ve done all of the above steps, you can open up a command prompt, navigate where you downloaded the Android 4.2 zip file and run “adb sideload 094f6629314a.signed-nakasi-JOP40C-from-JZO54K.094f6629.zip” and probably have a measure of success.
Step 4: Reboot
Lockscreen widgets, multiple users, daydream, gesture typing…