Upgrade unsupported Windows Phone to Windows 10 Mobile



Does this tutorial applies on me? Brief explanation

Are you a owner of a Windows Phone device? Running Windows Phone 8.1 Denim? Excited about Windows 10, but… your phone doesn’t const on supported devices list? (e.g. Lumia 530).
Then this tutorial might be what you are looking for. I have a Lumia 530 and since ever joined the Windows Insider Program. I was able to enjoy several Insider builds, till the day that my phone left the list of supported devices due to low internal storage (4GB). Like my device, others also were excluded from the list over time. While this tutorial is specially dedicated to Lumia 530, because I have only tested on it, you can also apply it on other devices that have 4GB and the minimum of 512MB of RAM. You also need your device to be running at least Windows Phone 8.1 (8.10.14219.341). If you have a Lumia, I am pretty sure this will work just fine for you.

Before you do anything, I just want to make clear that if your phone is not supported by Windows 10, you should be sure about moving on. Essentially because there is a slight risk of bricking your phone (never happened with me and I am using this process for months now). So, don’t blame me or the tools developers if anything happens to your device, it’s your own responsibility.

What’s the trick?

On this tutorial, I will explain you how to upgrade any unsupported Windows Phone 8.1 device to Windows 10 Mobile. While the Windows 10 doesn’t roll out publicly, the trick is to edit at least two registry key values (related with device model). Doing this will tricky the phone updater and will provide you Insider builds, once you apply and join any Ring. At this moment, joining any Ring (Fast, Slow, Release) from a Windows 8.1 device will always give you access to 10586.107 (haven’t tested if build 10586.164 is available though).

You will need…

Let’s just make sure you have everything before move on. On this list you will also find XAP files. XAP files are packages or “installers” of Windows Phone which can be deployed on your phone using Microsoft developer tools.

  • Lumia device running Windows 8.1 Denim (at least 8.10.14219.341)
  • SD Card with at least 2GB free memory. Higher classes mean faster update process. Just to give you an idea, if  I use an Class 4 SD Card, the upgrading process (gears) take about 4 hours, while using Class 10 SD Card it only took 1 or 1h30 hours.
  • Windows Phone 8/8.1 SDK. You can get a Lite version here, although if you have Visual Studio 2012/2013/2015 you probably have this installed. Check under Start Menu < Windows Phone 8.1 SDK. On bottom of this article, just check how to use Windows Phone 8.1 SDK Lite (soon).
  • CustomWPSystem_0601.xap
  • CustomPFD003.xap


1- Register your device with a Licence Developer. On WP8.1 SDK run Windows Phone 8.1 Phone Registration. Note that you find this executable under Windows Phone 8.1 SDK on Start Menu. You should get a successful message. Make sure during the process your phone is not locked.
2- Deploy CustomWPSystem_0601.xap using Windows Phone Application Deployment 8.1.
3- Go to the Store, install Windows Insider and Preview for Developers apps. Move the Preview for Developers to SD Card memory. You can do it by opening Storage Sense (you can find on Settings or App list)
4- Move CustomPFD003.xap to SD card. Using Windows Explorer on PC.
5- Open CustomWPSystem (check App List, if the deployment was successful you will find it)
6- Give it SD Card permissions. How? Tap the red label SD Card Permissions and browse to SD card, open it and the apply.
7- Select Preview for developers app. By default, this one is selected if you use the version I mentioned.
8- Tap Select Xap. Now, browse to SD Card and select the CustomPFD003.xap file.
9- Tap Apply XAP and wait.
10- Go to App list, open Preview for developers. You will notice the icon is different. Open it.
11- You need to change two registry keys values. Browse to HKLM/SYSTEM/Platform/DeviceTargetingInfo
12- Change the following keys:

  • PhoneManufacturerModelName (e.g RM-xxxx_xxx) [typically, may have more or less numbers]
  • PhoneModelName (e.g Lumia 535)

Q: What do I type?
A: The trick here is to type and RM code and correspondent name, from a device which supports Windows 10. I recommend you to use a model from 5xx family if you are owner of Lumia 530. I have tested 535 and 532 and always went well. You can get those codes on Microsoft websites. Open https://www.microsoft.com/en-us/, click Support < Lumia Devices and select some phone that is supported by Windows 10.

Q: Can I really choose any phone code? Won’t damage my phone?
A: You can. In spite of having a Lumia 530, I can get the ROM from Lumia 950 for example. Drivers won’t be a problem. The system is protected and will always get the right ones for your device. Despite you can select any RM code, I strongly recommend you to choose one from your family device, for example, for Lumia 530, choose 5xx. Chossing Lumia 640 RM code, which I also tested, requires more memory because the ROM requires more or less a extra 100MB free space. This is not really relevant because we are going to use an SD card to do the update.

13- Once you edit the Registry, let’s fill the phone memory.
Q: So far we have been kind of worried about phone available memory. Why now I am going to full it?
A: Well, I think there is a problem here from Microsoft side. If you try to update normally, you probably will get the low storage error message and it always says that the update requires 900MB (+/-). That’s not true. That might be the download size, although extra space to do the update, and 1,40GB are no longer enough for me. Ok, but I have an SD Card, why the phone doesn’t save the update there? Windows will always TRY to save the update on phone memory (because is safer and faster). So, you might be asking how Windows decides where to download? Free space is the answer. The phone checks the server and it’s like “Well, I need 900MB to the overall update. The phone memory has more than that, so I save the update there”. And this is why we will fill the phone internal storage. This is just a way to force the operating system to download the update to the SD card and not to your phones memory.

14- On the PC, run command prompt as administrator. We will use fsutil
fsutil performs tasks that are related to file allocation table (FAT) and NTFS file systems, such as managing reparse points, managing sparse files, or dismounting a volume.

fsutil file [createnew] <filename>

Example (1 GB dummy file)

fsutil file createnew C:Dummy 1000000000

My example generates a file with approximately 1 GB. Choose a size that will fill your phone memory till you have less than 700MB, to make sure that the phone downloads the update to SD Card.
Move the Dummy file to phone memory.
15- Join Insider program using Windows Insider and join any Ring. Users on Windows Phone 8.1 will update to build .107 even thought .164 is out. (?)
16- Check for updates, go to Settings < Phone Updates.
17- Once the download starts, go to your phone memory and delete the Dummy file.
Q: Why do I have to delete it?
A: Our goal was just to force update through SD card and we achieved it. So, we can delete it. Actually, you MUST! If you don’t delete it, when your reboot the device to install the update, it will fail. Not sure why, but I think it can’t delete the dummy file for some reason.

You will need to patiently wait, till the process is over. Hope this works fine for you. Leave a comment below about your experience.

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