I'm getting old, and my uninstaller proficiency is dubious these days ...

Some years ago I would have given this a try, but each time I reinstalled MFS, and then uninstalled it, I forgot to make the test:

- If we save the contents folder ( under which he two main install folders lay ) between installs, can we use it to rush the install instead of the installer having to pick some 30 G each time ?

I have the DVD version, so at least that part is easy on the net, but it came to my mind that saving the main folder, which I usually point to my "F:" drive, might make the re-install even faster, f between installs there was no update ?

I've backed up and replaced the big caches directory, the 90-100gb one. If you aren't suspicious of the data being the cause of whatever reason you are reinstalling you should be good there to save the time and bandwidth of downloading that whole mess again. But I've only installed from Steam or Xbox. They always reinstall with the latest version. If you are installing from the DVDs it's going to be installing from the original release version I assume. The first few versions where install nightmares. So if there's someway to start your install from the latest release you may have better results. Or I'm just confused and the DVD version goes and gets the latest version initially when it is installed?

28 minutes ago, Dylanear said:

I've backed up and replaced the big caches directory, the 90-100gb one. If you aren't suspicious of the data being the cause of whatever reason you are reinstalling you should be good there to save the time and bandwidth of downloading that whole mess again. But I've only installed from Steam or Xbox. They always reinstall with the latest version. If you are installing from the DVDs it's going to be installing from the original release version I assume. The first few versions where install nightmares. So if there's someway to start your install from the latest release you may have better results. Or I'm just confused and the DVD version goes and gets the latest version initially when it is installed?

agreed. MSFS is smart enough to check and understand what's missing and fill in / re-download the missing files. did this a couple of time when I deleted on purpose some file/folder in /official when trying to indentify a culprit for a missing splash screen image and to force a clean reinstall of those files.

Yes, after the DVD install finishes, the first time we start the sim it fetches usually around 30 GB to update it to the latest build.

The idea is to save the folder under which the "Official" and "Community" folders lay in a backup, so that the next time I do an install, before I start the sim I copy that backup back into place, making sure I chose the exact same folder names, and that way avoid having to re-download it...

4 hours ago, jcomm said:

The idea is to save the folder under which the "Official" and "Community" folders lay in a backup, so that the next time I do an install, before I start the sim I copy that backup back into place, making sure I chose the exact same folder names, and that way avoid having to re-download it...

This worked for me when I installed MSFS on my new machine. In my case - via Microsoft Store - I copied from the old machine that folder (E:\MSFS) to the same drive letter on the new machine and then proceeded to install from the Microsoft store. When the initial install on the standard place (somewhere on the C:\ drive) then asked me where I wanted to install MSFS I simply pointed it to E:\MSFS and after 30 seconds of checking it started loading the sim. 

This saved me  from having to download about 100 GB again.