No one asked "how do i prevent game updates?" all of you who are providing info like this;
neomonny7 wrote: [Bring up the galaxy launch page for the game. Click the button to the right of the Play and Synch buttons. Choose "Manage Installation" and then choose "Configure..." and then uncheck "automatic updates to newest version."]
you are wrong, and spreading bad info. comprehend the question provided before posting. it might just save you from looking like a fool, or worse.. a troll.
OP was ChWooly, with the question: "How do you turn off the Auto update of GOG Galaxy?"
GOG Galaxy is a game launcher/dl'er CLIENT program/software/application. The CLIENT can be installed on a pc, -without- even one game in the library. Until ChWooly says otherwise, its clear to me that ChWooly wants to put a stop to updates to that Client program.
"VanishedOne" and "apfelnymous" posted the best answers so far to restrict the CLIENT update process. however. "apfelnymous" posed a in-CLIENT answer relating to a global setting. Without illustrating a settings path to said option. And thus i have failed to find said setting (though i would very much like to.) my version of GoG Galaxy CLIENT is 2.0.73. There in all i could locate was options for disable GAME updates. Not CLIENT updates.
For Clarity, could someone who is able to access the option "apfelnymous" spoke of, post a textual or image based path of settings, to access said option? (a mock up might look like the following: Settings > Notifications > ClientUpdates > ☐Allow_GoG-Galaxy-Client_Updates☑ as a fictional example only)