I have had the Microsoft Store version since Sept. 2020 and rarely have had problems. I have all updates installed, Windows 10. Today I tried to restart the sim after experiencing poor frame rate on a VR multiplayer session. The icon I normally use was unresponsive. No message, just nothing happens. I went through normal troubleshooting - reboot PC, use repair then reset in the app settings (no effect), then uninstall. Uninstall was weird because it happened very fast and the space on my C drive didn’t change. I reinstalled the XBOX application and this time, uninstall of MSFS took a long time, and it finally said it was ready to play. But oddly only 1.02 GB was installed, and when I click Play, still nothing happens, and nothing shows up in Task Manager. Sometimes I got security prompts (“allow this app to make changes?”) but no error messages that I can find.
I uninstalled again, rebooted, ran Install, same thing. I tried several more times (I know, that’s insanity, right?). I tried running anything I can as Admin. I cleared more space on C drive and defined a different install directory. It says 123 GB required but again only 1 GB is installed and nothing runs or shows up in Task Manager.
My Win10 is up to date and other applications are working fine. I’m willing to “start from scratch” but I thought that was what Uninstall meant! I suppose I can reinstall Windows or take this as my cue to go to Win11. Open another can of worms? Or maybe take a forced vacation from flight sim to work on other hobbies? Spend time with my wife? 
Thanks for any advice!
Yes definitely make sure you get rid of any left over files. There’s usually a couple like the WPsystem folder and another couple.
Also, the Xbox app will download only 1GB then the game should launch. Once the game launches then you will see the 123GB download start to make progress.
When was Groundhog Day moved to May? Thanks for this advice. It’s what I have been trying to do about a dozen times today with some variations. Same result every time. The Store app now always says “Install from Xbox app” so there’s really only one method. When it installs the 1 GB, I get a couple of approval dialogs for some normal looking thing that wants to make changes. I search and don’t find any left over files. When Play button turns green, I click it, but nothing happens - nothing is launched, no changes in Task Manager.
One biggish change is Win11. When I was about to try reinstalling Win10 I decided to go to Win11 instead. It installed with little trouble and my other stuff still works OK. But MSFS is still DOA. Same exact behavior.
How does Windows “know” this is not a fresh install? Is there a config file somewhere? Registry entries? Windows seems to remember my user ID even when I sign out of the XBox app (all my apps are still listed, on the PC I guess). My next desperate thought is, what if I buy the game again, on Steam? I could just buy the Standard version since I have a million third party addons. That would install in a different directory with different authorization codes I suppose. Saving some of this aggravation would be worth $60 to me!
Thanks again.
Just for closure…
I tried a few other things after installing Windows 11 and nothing worked so I did buy the standard version on Steam. Took forever to download 123 GB but it works. Today I need to recreate all my control settings and set up Addons Linker for the new Community folder. I also need to install SteamVR and get that working with the HP Reverb G2 (I hope).
Thanks again for the help. It’s a shame to abandon a $120 software purchase but my time and sanity are worth $60 to me and it’s the same sim that will work with all my addons. I don’t need XBOX compatibility.
Hi, FlyingSinger20.
I had exactly the same experience yesterday as you.
In the morning 1 flight → no problems
In the afternoon → sim did not start up anymore . No messages.
In the process of troubleshooting, decided to uninstall completely (Long overdue).
But as you, I could initially only download the 1Gb through the store and the installation manager did not launch as this would be the next step in the installation process.
Resetting the Windows Store app solved this problem and then I could redownload/reinstall the whole sim.
Unfortunately after the new installation yesterday, the sim still did not start . Again with no messages.
As I meanwhile read here on the forum that there were problems with XBox services, decided to wait and this morning XBox services were restored.
But still no startup of the sim.
Turned out that the folder where the sim is installed (Default location) was set to read only.
After removing the checkbox for read only , all is good again. (Flying with the store version on Win11)
No idea how this is even possible or how this happened.
I understand your arguments for migrating to the steam version 
I do have probably a little more free time (No wife)
Meanwhile with the weekend almost over, all my addons (AC and scenery) are reinstalled. Remains only TDS GTNXi and pushback express to reinstall.
Maybe with this info you can get both version (Steam and store) up and running 
Thank you for helping me continue to beat my dead horse, giving me hope that perhaps it’s “only resting.”
That’s very interesting and gives me some other things to try. I have managed to get the Steam version running with my favorite addons and something close to my control settings. But strange things happen with Steam and I learned that even if I have folders for “Premium” Asobo aircraft, they won’t run with the Standard version. Not surprising and just a test since I mostly fly addon planes. I even got Steam VR to work with my G2 though the quality is not as good without the OpenXR Toolkit mods. VR had been working very well for me recently.
So it would still be nice but not essential to get back to running the non-Steam version, and it appears it might be possible, though MMMV (my mileage may vary). I do have a wife though not a job (retired) so my problem may be more impatience than free time per se.
Thanks again!
Bruce
Love the expression
There are a lot of usefull tips here on the forum, unfortunately not always leading to results.
You might consider running the command ’ sfc /scannow’ at a command-prompt (Administrator).
This checks the integrety of your OS’ es system files.
Good luck
John
Thanks for the reply John, I tried that already. It is so strange and weird. I had 24 stored profiles for different planes I flew, I had modified the default settings and they were saved by name. I can’t find the /wgs folder that should be in SystemAppData folder. Rumor has it all profiles are stored there.
Do you remember which folder. You changed from Read Only? My installation with DVD version went into numerous locations. Thanks