OSes

Experimental build boots on Raspberry Pi 5, but for now the joy is mostly in getting there

ReactOS, the open source project aiming to recreate Windows NT, has reached a new milestone: booting on ARM64.

The ReactOS team cautioned that the build was "still in an experimental state," while encouraging users to try it. Screenshots show the project running on ARM64 (via QEMU) and on a Raspberry Pi 5. 

ReactOS recently celebrated 30 years since the first commit to the project's source tree, with the current development targeting Windows Server 2003 compatibility. We last covered it in 2025 and came away impressed by its faithful recreation of the Windows golden age. 

Unlike WINE, which layers Windows applications support onto Linux, ReactOS recreates the NT kernel from scratch, right down to driver support. 

The ARM64 port is very much a proof of concept - there's precious little that you can actually do with it yet. But watching that familiar Windows desktop appear on the hardware is genuinely joyful, and dismissing it as an "it boots" milestone would be a disservice.

Getting ReactOS to boot on ARM64 is no small feat; a ReactOS contributor spent eight months getting the code working. It requires a UEFI ARM64 system with GICv2 or v3 enabled, supports boards from ARMv8-A onwards, with the Raspberry Pi 5 being a special case.

The Register had a go at booting it on a Raspberry Pi 5, and met with mixed results - getting it running is not for the faint-hearted. The project isn't kidding when it calls the process experimental, though criticizing it for stability or app support would be unfair at this stage. ReactOS bills itself as "an alpha-quality operating system," which means it should really only be let loose on a sacrificial device.

That said, perseverance has its rewards, and while there isn't much a user can do with ReactOS on ARM64 at this stage, reaching the desktop at all is quite the milestone.  ®