Now that I know when Windows 10 will be released let's go to the important thing.

I'm aware that it's unfinished software different than what Developer Preview is and know it can brick my phone.

How to get it?


Microsoft just announced it (on February 12, 2015).

So at this time the following phone models are supported (possibly with more to come):

Alcatel OneTouch Fierce XL

BLU Win HD W510U


Lumia 430

Lumia 435

Lumia 532

Lumia 535

Lumia 540

Lumia 550

Lumia 635 (1GB)

Lumia 636 (1GB)

Lumia 638 (1GB)

Lumia 640

Lumia 640 XL

Lumia 650

Lumia 730

Lumia 735

Lumia 830

Lumia 930

Lumia 950

Lumia 950 XL

Lumia 1520

MCJ Madosma Q501

Xiaomi Mi4

If you have one of these devices, here's what you have to do to install the Windows 10 Technical Preview:

  • Register as a Windows Insider
  • Download the Windows Insider app on your phone
  • Launch the app and log in with your Microsoft Account
  • Choose how often you want to receive new builds
  • Accept terms / warranty information, then hit the check button
  • Afterwards go to Settings -> Phone Update and install Windows 10.

Be sure to have your phone charged and connected to Wi-Fi to make the download and install process as smooth as possible.

Microsoft warned that it is a very early build and can brick your phone forever.


You can install Windows Phone 10 TP on other phones as well using the following process (found here):

Warning: you could brick your phone

I recommend reading this article before proceeding. Some key points:

If you do not have a phone that can get Windows 10 yet, you are not missing a whole lot.

There are significant risks. Those risks are exponentially higher for those with Samsung or HTC devices, as they are harder to reflash should anything go wrong. Lumias have some recourse with the Lumia Software Recovery tool found here on Microsoft's servers.

It is not clear what happens during the next update. The supposed Windows 10 restore option (which you can find here) is not working for everyone, even on legitimate devices.

The process

From a high level this works by using FiddlerCore to intercept the traffic going to the Microsoft WPflights server that controls the Insider app and responds with our own custom data. The app accepts registry editing information from the web responses and acts upon that. This allows us to write stuff to select locations in the registry. In the case of the Windows 10 Preview, it appears to only look for your phone's PhoneManufacturerModelName to decide if it should be offered previews. Windows Update also checks this value.

  1. For the Lumia 1520 (and other phones?) reset your phone using the Windows Phone recovery tool. This is done to free up space on your phone. You can try without resetting but may get an error after it tries to download and install the update.

  2. Install the Windows Insider app on your phone (you will need to have a store account configured)

  3. Open the insiders app and go to the about options in the app bar and screenshot/make notes/email the settings to yourself. You may need this later.

  4. Download and extract the WPInsidersHacks app to your computer

  5. In order for this to work, you need to update the RM value that's appropriate for the "fake" phone you're trying to emulate. This is dependent on the phone type and location/carrier. The WPInsidersHack tool should work for ATT (US). For any other carrier/Country you'll need to edit the WPFlights.xml file found in the same folder as the WPInsidersHacks tool. There are two entries to edit:

    Near the top of the WPFlights.xml you'll see this:

            <Value>RM-975_1005</Value>  <--------------Change this to the appropriate "Fake" RM code

    Near the bottom of the file, you'll see this:

            <Value>NOKIA</Value>  <----------- Change this to YOUR current phones manufacturer
            <Value>RM-940_nam_att_200</Value>  <-------------- Change this to YOUR current phones RM value

    To find the appropriate code for you phone is the most difficult task here. I had a buddy that had a Lumia 635 phone for my carrier (T-Mobile US). I asked him to go to the Windows Insider app and tell me the RM code. (RM-975_1020). You can also try searching the forum linked above as others have found some that work there as well.

  6. Save the edited file above

  7. Start the WPInsiderHacks app on pc, approve any firewall requests

  8. Connect the Windows Phone to the same WiFi that your PC is on. Edit the settings for the WiFi connection to turn on the Proxy and set it to use the PC’s IP address and enter 8877 for the port

  9. Open Internet Explorer on your phone and navigate to http://[pc.ip.add.ress]:8877 where [pc.ip.add.ress] is the IP address of the PC running the WPInsidersHacks app

  10. Tap on the link at the bottom to the fiddler root certificate

    Snapshot of website.  Click very bottom link

  11. When prompted click open and then install to trust the cert and ok at the confirmation

  12. Run the Windows Insider app and tap get preview builds

  13. Tap on "Set to ATT Lumia 635" and click the arrow at the bottom (Note this will actually set your phone to the "fake" phone you used above.)

  14. Accept the agreement and click the check mark at the bottom. The app will close.

  15. Now clear your proxy settings and run the Windows Insider app again

  16. Tap get preview builds and login with your Microsoft account

  17. Select the fast branch (if you’re reading this of course you want the fast branch) and click the arrow at the bottom

  18. Go into the phone settings and check for updates. With any luck you should have Windows 10 there for you to install.

  19. After install, follow steps 7 - 12

  20. Tap on "Set to ATT Lumia 1520" and click the arrow at the bottom (Note this will actually set your phone back to the original RM values as long as you updated them earlier in step 5).

  21. Accept the agreement and click the check mark at the bottom. The app will close.

That's it!!! You now should be able to enjoy Windows 10 TP for your phone. I followed these steps for my HTC One M8 for Windows on the T-Mobile (US) carrier. Everything seems to be working fine with a few things missing that were HTC specific. So be warned that this is truly a hack and things are most likely going to be missing. Also note that Windows 10 TP is very very buggy.


Bricked my phone while upgrading to Windows Phone 10 Technical preview.

Some additional points you can of take care of:

Go for slower builds. Although you may a feature a week delayed, chances of crashing your phone is less.

@thomas explained in short and the perfect way to install Windows 10 Technical preview.

In case it fails and your phone stops responding, you can follow these steps :

Download Lumia Software Recovery Tool from Microsoft's website. After download, connect your noit-responding phone to your system, and it will detect it. Once detected, the software recovery tool will download the appropriate firmware for your Windows phone and everything will be back on track.

One thing, I didn't read here is: BACK UP YOUR PHONE.

And in case you brick your phone, here's the steps you can follow to get it back up and running.

Windows 10 Technical Preview failed? Return to Windows Phone 8.1 from Windows 10 Technical Preview


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