https://www.overclock3d.net/news/software/how_to_get_halo_reach_s_pc_version_to_launch_with_xbox_game_pass/1
 
Halo: Reach has had an incredibly successful launch on PC, having already achieved player counts of over 100,000 on Steam, while also releasing on the Windows Store and via Xbox Game Pass for PC. 

Sadly, the PC version of Halo: Reach on the Microsoft Store, and Game Pass for PC (beta) app will not boot for a large number of PC players, preventing a large number of PC gamers from playing Halo's first main series PC release in well over a decade. Thankfully, there is a fix for the issue. 

343 Industries is actively investigating a fix for this issue, but for now, there is a "viable work-around" for PC gamers. Please follow the instructions below if Halo: Reach will not launch on your PC via the Microsoft Store or Xbox Game pass for PC (Beta) app.

1. Press the Windows key to bring up your OS' search menu
2. Search your PC for "Halo: The Master Chief Collection"
3. Select the game
4. Launch the application

To create a taskbar shortcut for Halo: The Master Chief Collection, follow the instructions below. 


1. Locate the game on your PC using steps 1-3 above
2. Right-click the game tile
3. Pin the tile to your start menu or taskbar as desired

Using this method, PC gamers should be able to get Halo: The Master Chief Collection running on PC. 
 
Some very useful info here. Hope it helps those who are having game launch issues. 

All went very smooth for me. I bought, downloaded and installed through Steam. When starting the game for 1st time I had to log in to Xbox live which I was not thrilled about. Champaign played well with no settings changes. Played through the 1st 3 levels pretty easy at Normal setting. Considering the game's age graphics were not bad and audio was decent. I have not played multiplayer yet but looking forward to it. One can hope it goes as smooth as the rest so far.