Reinstalling Windows/FS2020 Without The Big Download

Hopefully of value to others. A 100GB download is a pain for many.

I had Windows do a death spiral. It was an old installation and there was accumulated cruft in the registry. It was still working ok but I started getting FS2020 CTDs at first when I started WMR after FS2020. Then I started getting them even after everything was running and I was strictly in the sim. Then Windows update last week couldn’t finish and threw a corrupt file error. I had other Windows weirdness too so decided it was finally time for a full Windows reinstall with all the pain that brings.

I run Steam and had put or moved all games/sims onto solid state drives. (Windows is on an SSD too but a smallish one) Having all Steam apps on other drives is valuable. Turns out when you install Steam on a rebuilt system and go to “download” apps that were already installed on the old system, if you pick an app in a Steam repository/directory to “Install” and tell Steam to put it in the original/existing location, Steam is smart enough to see it’s already there and just “discovers” it. No download. Even better, every other app in that same repository is also discovered and they all automatically reconnect. It was really nice to discover Steam does that. Anything in the main (default) C drive Steam repository will have been blown away and need to be redownloaded, though. There’s some Steam assets stuff that seems to get caught up in that.

So first step with FS2020 was to reconnect it to Steam. Once I did that, I launched the Steam FS2020 stub which then told me it needed to download 109GB even though all the files were already sitting on a drive. Even if you point it at the installed location, it doesn’t seem to run inventory again and wants to do a full download. In contrast to Steam which automatically discovers files and avoids downloads, FS2020 only does that if you go with a stock C drive install. The problem with that is if you blow away Windows, you also blow away FS2020.

I put FS2020 on a high speed m.2 drive just for performance but a non-standard location trips up the FS2020 installer/updater. If you edit the last line in “User”/AppData/roaming/Microsoft Flight Simulator/UserConfig.opt to point to the location where the Official and Community directories do live, the loader will see what it has and only grabs anything it might need. For me it just needed to run the inventory and then it dropped into the main menu.

Avoiding the big FS2020 download is pretty easy if you don’t want a full, fresh, install. Early in the release, there was talk that updated versions and full downloads were different and some bugs were only fixed with a full download. Pretty sure I saw some of that when a full redownload fixed some original release download issues. But for those that install or move FS2020 to a nonstandard location and don’t want to download again, that one edit can save lots of trouble.

And lastly, I was afraid I would get caught up in the DCS deauthorize/authorize tail chase but couldn’t find a way to deauthorize my old DCS modules in Steam or DCS. I did a full game backup in Steam for DCS and crossed my fingers. Didn’t even need it. When Steam reconnected with the repository that had DCS in it, it all just worked. I tried a few modules and no authorization issues at least so far so I think it’s good.