Microsoft released the Windows 10 Technical Preview for phones only to a hand-full of low-end devices, leaving many Windows Phone owners without the chance of testing the new operating system (temporarily). However, soon after the release one XDA developer has managed to create a method to make the Windows Insider app think that the phone is actually one of the supported devices for the preview.
The tool is specially crafted to trick the Windows Insider app making think the phone is a Lumia 635, which is one of the supported phones to install the latest preview of Windows 10 for phones.
This method mandates to change the ID of the phone and many users are reporting successful upgrades to Windows 10. However, the only problem is that after the update there is no access to update through the “phone update”. To get regular updates you must go through a 17-step process, which also involves correctly knowing the country code for the headset you’re trying to update that is not easy to get, but it’s not impossible if you know how to use Google.
According to the XDA forum users were able to upgrade various Windows Phone 8.1 to Windows 10 preview for phones, including HTC 8X and One M8 for Windows and various Huawei phones. This upgrade method does not require devices to have a SD-card slot, which indicates that other Windows Phones, such as the Lumia 930, 925, and 920 can be upgraded too.
I won’t be posting the steps on how to go through upgrade unsupported Windows Phones to the Windows 10 Technical Preview for phones, because it’s extremely important to understand that this is not a supported method from Microsoft. The software giant didn’t release the preview for the operating system to more phones, because there are a lot of issues.
If you decide to upgrade your unsupported phone to Windows 10, try it, but only knowing that you understand what you’re doing.
Microsoft decision to release a version of Windows 10 for phones to a small number of devices was made based on feedback, where users opted to get an early build of the software on fewer devices, rather than wait longer for more support.
Source XDA-forums via Neowin