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Microsoft Office is now 64-bit for Windows 11 on ARM bringing improved performance and better compatibility

Office Updating Windows 11 Insider
Office Updating Windows 11 Insider (Image credit: Daniel Rubino / Windows Central)

What you need to know

  • The 64-bit version of Office for Windows on ARM is now rolling out to Insiders.
  • The app uses new technology from Microsoft called ARM64EC, which lets it use x64 plugins and code compiled for Windows on ARM together.
  • To test Office for Windows on ARM, you need to be an Office Insider and running a preview build of Windows 11.

Windows Insiders can already test out the first preview build of Windows 11. Now, they can get their hands on another preview piece of software from Microsoft, the 64-bit Office for Windows on ARM. The app has been recompiled for ARM architecture, which brings better performance and improved efficiency while using less memory. Microsoft announced the ARM-optimized version of Office last week, but it is now rolling out for testing.

Microsoft explains that the new version of Office should have overall better peformance, handle large documents better on devices like the Surface Pro X, and now work with 64-bit add-ins when compared to the fully-emulated version of Office.

The previous version of Office ran mostly native at 32-bit, with parts of the app presenting itself as x86 for add-ins to work correctly. Today's shift brings Office up to a more modern 64-bit architecture while also being more native for ARM.

Source: Daniel Rubino / Windows Central (Image credit: Source: Daniel Rubino / Windows Central)

Microsoft enabled Word, PowerPoint, Outlook, OneNote, and Excel as ARM64 apps. Other Office apps will still run in x64 emulation mode.

The Office apps utilize a new technology from Microsoft called ARM64EC, which stands for ARM64 Emulation Compatible. This technology allows developers to mix and match code that's built natively for ARM64 alongside code that runs in emulation. As a result, apps with dependencies that don't natively support ARM64 can run partly as native apps and partly in emulation.

Office has x64 code and legacy add-ins that aren't built for Windows 11 on ARM. With ARM64EC, Microsoft can rebuild large portions of the app to run natively on ARM devices, while the older components run in emulation.

To test out the new Office apps, you need to run a device with an ARM processor, such as the Surface Pro X or Galaxy Book S. You also need your PC to be on a Windows 11 Insider preview build.

If you have the right hardware running Windows 11, you can then follow these steps:

  1. Uninstall any 32-bit versions of Office you have on your PC.
  2. Install the latest version of Office from office.com (your PC will automatically install the ARM-optimized version of the Office apps).
  3. Join the Office Insider program.
  4. Update your Office apps to the current Beta channel build.

Microsoft has a guide on how to join the Office Insider program if you need more help.

Sean Endicott
Sean Endicott

Sean Endicott is the news writer for Windows Central. If it runs Windows, is made by Microsoft, or has anything to do with either, he's on it. Sean's been with Windows Central since 2017 and is also our resident app expert. If you have a news tip or an app to review, hit him up at sean.endicott@futurenet.com.

10 Comments
  • I followed the guide (uninstalled) and then installed from Office.com.
    It still says 32-bit to me. I tried also installing the 64-bit but says the ProX is not compatible with it. What should the "ABOUT OFFICE" say? Will it still list 32-bit or something else?
  • Are you on the Office Insider program? That's distinct from the Windows Insider program.
  • I had the same issue, it doesn't tell you under the Office account settings and will continue to say 32 bit, but when you go to the task manager it will say that Word, Excel, One Note, and Outlook is using Arm 64. I never checked before, and maybe that always came up, but those programs are using Arm for sure. If you open Access under the task manager, it will still say x86.
  • It sounds like you're not using the version discussed in this article if you're still using the 32-Bit version. ARM64 support is part of the 64-Bit Microsoft 365.
  • I also had this problem before, and it's because I uninstalled the office through apps and features in the settings apps. Once I uninstalled the office using the old add and remove program of the control panel, I could install the office using the default installer from office.com and got the X64 version of the office. After that, I joined the office insider, and I got the arm64 version of the office. when I tried to install the office through the X64 installer, it said that my Surface Pro X is not compatible.
  • Apps and Features and Programs and Features link to the same uninstall programs.
  • Now, microsoft is going in direction on ARM
  • That guide doesn't work, you have to use the Office Deployment Tool and modify the setup XML file to properly install the beta on Windows on ARM.
  • Any idea when this will RTM? Can't wait for Windows 11, 64-Bit Office and finally 64-Bit support in general on my Surface Pro X.
  • I uninstalled the 32 bit version following the guide, installed from the 64 bit link on office.com, joined the insider program in the beta channel and after the subsequent install task manager shows that it is running the 64 bit ARM version. Not bad, so far.