Microsoft Prism is emulation engine it’s used in Windows on ARM, and the Redmond firm says it’s improved it again in the latest version of Windows 11, build 27744 released on the Insider channel for tests of the corresponding versions.

Microsoft has been pushing for the viability of Windows on ARM for more than a decade, ever since the launch of the Surface RT tablet. It was a fiasco that caused close to $1 billion in losses and, according to gossip, the beginning of the end for then-CEO Steve Ballmer, who was replaced by current Satya Nadella. Microsoft continues to try without success for two primary reasons: low level hardware and poor emulation of x86 applications.

Apple’s successful transition “brought the colors” to the rest of the industry, and the software giant is currently on a multi-trial run with Copilot+ computers that arrived with Qualcomm’s ARM chips. It seems evident that if Microsoft wants to finally make Windows on the ARM platform an alternative to standard Windows, as well as a competitor to Apple’s Macs, which have been out of reach until now, it is absolutely necessary that an emulator used to run non-native software improves performance and compatibility.

Microsoft Prism, enhancements

It should be remembered that the vast majority of Windows PC applications are still programmed for x86 processors. And there are thousands and thousands of previous ones used by millions of users. They must be emulated if they are to be used on ARM-based computers. Microsoft Prism translate the code behind it software built for the traditional x86-64 binaries used by Intel and AMD processors. The problem is that every emulator has performance and compatibility costs.

Microsoft is pushing app developers to create native software for ARMbut it will take time to change everything and the emulator will remain a core component for many years. And it must be acknowledged that improvements to Microsoft Prism have been constant. Following Apple’s example with its Rosetta emulation program, the Redmond firm offers developers the ARM64EC Application Binary Interface (ABI), which gradually allowed them to replace parts of x64 (64-bit) binaries in their applications with native ARM code to improve performance.

Latest Windows 11 Update Added improvements to several x86 CPU instructions to the emulatorincluding AVX and AVX2, BMI, FMA, F16C and more. Support for these features is already used in the retail version of Windows 11, version 24H2, to run applications such as Adobe Premiere Pro 25 on ARM. This version extends this compatibility to any x64 application under emulation Although 32-bit software programmed for x86 is excluded, this advance is very important because 64-bit software is really important here.

At the time, Microsoft assured that new Windows computers on ARM would have “faster app emulation than Rosetta 2”the latest application compatibility layer used by Apple to translate applications originally compiled for Intel x86 processors to Apple’s own ARM processors.

We’ll see if the promises come true. Supporting the vast Windows ecosystem and especially the Win32 applications that Microsoft would love to destroy but are used by millions of users is a titanic task and until now the main problem in running a viable Windows on ARM.