where i live the data rates are horrible. i just got done buying the gog version of fallout 4 so i could play fallout london on it. i wanted to go back to the original. just to play it some. and found out i would have to completely redownload the game. don't get me wrong. i'm used to having to re-install games all the time. it would be nice if that weren't needed. when it is though and likely, it would be nice if a option was given to keep the install files. so i don't have to fetch them from your server several times a day. ever time i get in the mood to play one version or the other

if i am ever able to. right now the data fees here are horrible. i can barely afford 400GB a month. and have to leave at least half of it so my SO can use the internet too

1. On the game details page, click Extras (to the left of the Play/Install button).
2. Download the offline backup installers there.
3. Games installed this way can be added to GOG Galaxy. Click the cogwheel in the top left, choose Add Games & Friends, then Scan Folders for GOG Games.

tried that. it told me to re-download part 8. downloaded the file it listed. it still fails the integrity check

edit: got past the check. tried a few things. main one the time it worked was deleting the file. then copying over the new one. might have just accidentally copied the file to the wrong area the first time