It's a less than ideal scenario, for sure, but if you're going all in on the Windows Mixed Reality experience then that means gaining access to everything on your PC.
While you can't manipulate and interact with your win32 apps like you can those from the Microsoft Store, you can at least use them while you're inside your Mixed Reality headset. Here's how.
- Make sure your headset is on and your motion controllers are connected.
- Press the Windows button on either controller.
- Select all apps.
- Scroll down until you come to desktop.
- Click the trigger to open it.
Inside Windows Mixed Reality, your desktop becomes the app and everything inside it works just in that same window. It's not the most user-friendly experience, but it will at least give you access to a web browser that isn't Microsoft Edge or apps like Photoshop should you have a desire to use these.
Once you click out of the desktop app window it'll go to sleep as with any other application and you can resize it and pin it to a wall if you so wish. It's one of those situations that it's good to have in a pinch, but it's not how you'll get the best Mixed Reality experience.