The Add a Non-Steam game to my Steam Library option can be found either under the Games tab or by clicking the Add a Game button in the bottom-left corner.

Click Add. You have now created a new Steam games library location on your PC where games can be stored, but you still haven't moved any of your games to that location.

Microsoft is starting to test its new aggregated gaming library in its Xbox PC app on Windows. Xbox Insiders will now be able to see their Steam and Battle.net games all within the Xbox app ...