For years, Microsoft’s journey with ARM-based Windows devices has been a long and winding one — from the early days of the Surface RT with NVIDIA processors to today’s Copilot+ PCs powered by Snapdragon X. But a major turning point has finally arrived.
With the October 2025 update (KB5066835), Microsoft is officially introducing AVX and AVX2 instruction support within Windows 11’s Prism emulation layer (versions 24H2/25H2). This marks one of the most significant upgrades yet for gaming, productivity, and creative workloads on ARM devices.
Prism Takes a Major Step Forward
Prism, Windows 11’s x86/x64 emulation engine for ARM, works by translating x86 instructions into ARM64 in real time and caching those compiled segments for reuse, which helps reduce translation overhead. The latest update enhances Prism by adding support for advanced vector instructions — AVX and AVX2, allowing emulated apps to access a wider instruction set that was previously unavailable on ARM systems.
This change dramatically improves software compatibility and stability. Many games and professional applications that previously failed to launch or crashed during execution can now run under emulation.
Community tests and early reports from Windows Latest confirm that Steam games, which once refused to load, now start and are even playable — though performance may vary depending on the title. Similarly, demanding programs such as Adobe Creative Cloud tools and other AVX-dependent applications now behave far more reliably.
While emulation still introduces some performance overhead, and native ARM drivers remain crucial for optimal results, the overall compatibility threshold has been significantly raised — giving developers and users far fewer limitations when running legacy Windows software on ARM-based PCs.
How to Check or Enable AVX/AVX2 Support on Your ARM Device
Microsoft has added a simple way to verify whether Prism AVX emulation is active on your device:
- Locate the app executable (.exe) you want to check.
- Right-click > Properties > Compatibility tab.
- Look for the option labelled “Show the latest emulated CPU features.”
- If the box appears, you can toggle it on to enable the feature manually.
- If instead you see “Hide latest features,” that means your system already has it enabled globally.
To use this feature, your device must be running:
- Windows 11 24H2 (Build 26100.6725 or newer), or
- Windows 11 25H2 (Build 26200.6725 or later),
and must have the October 2025 KB5066835 update installed.
Why AVX/AVX2 Matters
AVX (Advanced Vector Extensions) and AVX2 are SIMD instruction sets that have been standard in Intel and AMD processors for over a decade. They are critical for physics simulations, video encoding, 3D rendering, and many libraries that modern software depends on.
ARM-based chips, however, lack native AVX support in hardware. Until now, that meant many x86 applications would crash or refuse to launch under emulation. By emulating AVX/AVX2, Prism bridges this gap, allowing software to “believe” it’s running on a full-featured x86 CPU — even if actual performance will still depend on emulation efficiency.
Step Toward ARM Maturity
This update marks a major milestone for Windows on ARM, bringing it closer to parity with traditional x86 systems in terms of compatibility and usability. Combined with Qualcomm’s growing performance gains on Snapdragon X Elite and X Plus chips, this move reinforces Microsoft’s vision of a power-efficient, AI-ready PC ecosystem that no longer sacrifices legacy app support.
In short, Windows 11 on ARM is no longer just experimental — it’s becoming a serious option for gamers, professionals, and everyday users alike.
