Unable to complete install, stuck on decompression

I had been part of the insider preview programme, and decided to change back to the stable version. Upon trying to start the game, it would not get past the decompression stage. Even restarting the sim, it would do the same on a different file. This is on a PC
I have tried the following:
Install on C drive (same issue)
Install on another drive (same issue)
Reinstalled both the xbox and microsoft store app (same issue)
Removed the:\Users\xxx\AppData\Local\Packages\Microsoft.FlightSimulator_8wekyb3d8bbwe folder before reinstall (same issue)
The drives are both M2 SSDs and last night it ran for 14 hours stuck. It is obvious there is some inherent left over data somewhere causing this issue.
Apart from a fresh install of windows, is there anything else I can try

You could try this:
https://flightsimulator.zendesk.com/hc/en-us/articles/360015760660-How-to-troubleshoot-download-Installation-issues

but I would recommend you see the this thread first:

Have tried, download speeds are fine, it is the decompression where it gets stuck

A lot of times, just deleting the folder the installation is stuck on will do the trick.
However, if you went through the Support Article, and all the linked ones that are in that, it may indeed be a Windows issue.

If you have an antivirus, try deactivating it the time of the installation.

So, brand new windows install, and exact same issue. Simply a terrible way to install a game.

Have you gone through all the articles that are linked in the Support Article?

If so, you could try this.
https://flightsimulator.zendesk.com/hc/en-us/articles/4409228619538-How-to-delete-a-cloud-save-on-PC-to-fix-some-loading-issues-or-reset-the-logbook

If you do a sim reinstall again, use Windows Apps and Features to uninstall it, and then delete all left over folders.
Restart PC and then try the install.

So having the same issue decompressing, when I got a BSOD. Changed my memory settings (3600mhz rated running at 3600mhz) so it ran at lower speed and has finished the install. So it appears to be a RAM issue.