Oddly, some factory image scripts, like the one for nakasi, wipe each partition manually first. The -w option instructs fastboot to wipe data.b) remove any mentions of fastboot erase userdata if you see any. For example, if the line reads fastboot -w update image-razor-jss15j.zip, it should now read fastboot update image-razor-jss15j.zip. If you skip this step, your data will be wiped. With your favorite text editor, edit (be careful not to run it by accident instead of editing) flash-all.bat (if you're on Windows) or flash-all.sh (Mac, Linux) and:a) remove '-w' from the fastboot update command. Proceed with this step if you want to keep your data intact.I use Total Commander, but you can use any tool that reads gz and tar, like 7-Zip. Unpack the tgz (tar/gz) archive into its own directory.It's a clean slate for these components - they'll flash cleanly over anything you have now. Download the full factory image corresponding to your exact model (for example, 2013 Nexus 7 Wi-Fi is razor), which includes the full system, bootloader, recovery, kernel (boot.img), and radio (radio not included for Wi-Fi-only variants).For security purposes, you can turn it off after we're done. Now go to Developer options and make sure you have USB debugging turned on. You also need to unlock your bootloader - a process that wipes your data.Įnable Developer options by going to the Settings -> About screen and tapping Build number until the OS unlocks the hidden Developer options menu. You will also need a MicroUSB cable to execute adb sideload, fastboot flash, and other commands. The SDK contains the latest version of adb and fastboot, which you will need for flashing files and issuing commands. In order to complete the steps below, you need to have the Android SDK installed. In some situations, not wiping user data may prevent the device from booting, in which case you'd probably need to go ahead with the wipe, but for simple OS upgrades from one version of stock Android to another one higher, wiping data should not be necessary. Note #2: If your bootloader is already unlocked, you have the option of skipping the data wipe during the factory image flashing procedure. You will want to back up what you want manually. Note #1: If your bootloader is locked, your data will be wiped for security reasons - there's no way around that.

Android kitkat img