Windows Phone 8 GDR3 was the last update for Windows Phone, adding a better screen resolution, full HD support, driving mode, improved connectivity, custom ringtones, and finally, the ability to close applications to your Nokia Lumia and HTC phone.
Upgrading to GDR3 (8.0.10521.155 and future test releases) is only available to developers, but if you can’t wait until Nokia and HTC release the update, you can do the update yourself by opening an account as a developer.
Please note, updating by this method may void your warranty.
How to upgrade to Windows Phone GDR3
1. Sign up in the Windows Phone App Studio
Go to the Windows Phone App Studio page and click on the ‘Start building’ button.
Sign up with your Microsoft account (it’s quick and completely free), and confirm that you accept the Terms of Use and register.
2. Install the Microsoft Certificate
You’ll get a welcome message from Windows Phone App Studio on your phone. Make sure that you don’t delete the message, as it contains the link to the Microsoft developer certificate.
Click the link provided to install the certificate. You’ll be asked to confirm if you want to add a company account. Once you’ve clicked add, the installation shouldn’t take more than a few seconds.
3. Install the Preview for Developers App
Now that you have the Microsoft certificate, open the Preview for Developers tab from your phone and install the application, which is also free.
4. Activate Preview for Developers
In your list of applications, you’ll now see Preview for Developers. Open the file, and accepts the terms and conditions.
Once it’s activated, a message appears that’ll let you know that Preview for Developers has been successfully installed. Now, manually look for the update in the options on your Windows Phone.
5. Find and install the GDR3 update
Go to Settings> Updates and look for newest version that you’ve just downloaded. Chances are that your Windows Phone will notify you immediately. Download and install the update.
6. Enjoy your Windows Phone 8.0 GDR3
After restarting your phone, Windows Phone will tell you that the system has been updated and list the update history. If you don’t think it’s worked properly, check for updates again; it might be that you have another update waiting.
The version number of Windows Phone 8 GDR3, which you can check in Settings> About, will be 8.0.10501.127, 8.0.10512.142, or 8.0.10521.155.
Although Microsoft is eager to stress that this update may make your phone’s warranty invalid, there’s nothing particularly risky about it installing the update. We’ve updated a Nokia Lumia 920 to GDR3 version without any problems.