If you are going to use Windows Mixed Reality hardware, you will need to install an additional program - Windows Mixed Reality for SteamVR. It is installed in the same way as SteamVR
In Steam installed on your PC, open the «Store»section and type Windows Mixed Reality for SteamVR in the search bar. Go to the program page
You will see a message saying that it is in your Library. To install Windows Mixed Reality for SteamVR, click “Use now”
Install Windows Mixed Reality for SteamVR by following the instructions in the installer