How To Install Latest Windows 10 Builds On Unsupported Mobile Devices ((INSTALL))
Build number 10136 was released on June 16, 2015, with a "migration bug" that required that existing devices on build 10080 be reverted to Windows Phone 8.1 using the Recovery Tool before the installation of 10136 could proceed. This migration bug was fixed a week later with the release of build 10149. Mobile builds of the Redstone branch till 14322 were halted for the device Lumia 635 (1 GB RAM) due to bugs.
How to Install Latest Windows 10 Builds on Unsupported Mobile Devices
Microsoft originally stated that all Lumia smartphones running Windows Phone 8 and 8.1 would receive updates to 10, but Microsoft later reiterated that only devices with the "Lumia Denim" firmware revision and at least 8 GB of internal storage would receive the upgrade. In February 2015, Joe Belfiore stated that Microsoft was working on support for devices with 512 MB of RAM, (such as the popular Nokia Lumia 520), but these plans have since been dropped. Upon the official upgrade release, some Lumia models, particularly the Lumia 1020 and 1320, were excluded despite meeting the previously announced criteria. Microsoft cited poor user feedback on the performance of preview builds on these models as reasoning. On October 17, 2017, Nearly 2 years after the Windows 10 release, Microsoft released an Over-The-Cable (OTC) Updater tool to bring all Lumias up to date to the latest supported Windows 10 build, even older 512 MB and 1 GB RAM unlocked devices such as the 520, 620, 720, 925, 920 etc. which were updated using the tool to Build 10586 (November Update).
Microsoft's work on handheld portable devices began with research projects in 1990, with the work on Windows CE beginning in 1992. Initially, the OS and the user interface were developed separately. With Windows CE being based on Windows 95 code and a separate team handing the user interface which was codenamed WinPad (later Microsoft At Work for Handhelds). Windows 95 had strong pen support making porting easy; with some saying "At this time, Windows 95 offers outstanding pen support. It is treating pens right for the first time." WinPad was delayed due to price and performance issues, before being scrapped in early 1995 due to touchscreen driver problems relating to WriteTouch technology, made by NCR Microelectronic Products. Although WinPad was never released as a consumer product, Alpha builds were released showcasing many interface elements. During development of WinPad a separate team worked on a project called Pulsar; designed to be a mobile communications version of WinPad, described as a "pager on Steroids". This project was also canceled around the same time as WinPad. The two disbanded groups would form the Pegasus project in 1995. Pegasus would work on the hardware side of the Windows CE OS, attempting to create a form factor similar to a PC-esque PDA like WinPad, with communications functionality like Pulsar. Under the name Handheld PC, a hardware reference guide was created and devices began shipping in 1996, although most of these device bore little resemblance to the goal of a pen-based touchscreen handheld device. A specification for a smaller form factor under the name Palm-size PC was released in 1998.
However, these are not hard requirements. There are plenty of workarounds available to install Windows 11 on unsupported devices that already run Windows 10. But there are several drawbacks to installing Windows 11 on an unsupported device.
Here is where things start to get a little complicated. While you can install Windows 11 on unsupported devices, the process is a little tedious. Also, you are bound to run into multiple errors. Therefore, it is advisable to back up all your important data before proceeding further.
PostmarketOS (pmOS), is a touch-optimized, pre-configured Alpine Linux that can be installed on smartphones and other mobile devices. View the device list to see the progress for supporting your device.