If GOG is intending to force Galaxy 2.0 on to me, I'd rather disable the client ability to update. I know it's possible, but I don't know how.

Before you go all "But galaxy 2.0 is the best thing since sliced bread" on me, let it be known that I don't give a s**t.

I intend to disable the update so that I never get 2.0. My mind is made up.

https://www.gog.com/forum/general_beta_gog_galaxy_2.0/will_galaxy_20_completely_replace_12/post4

(I haven't personally tested it.)

Disabling might work for a bit but I would imagine at some point GOG will stop old versions from being able to connect to their servers due to security reasons / compatibility reasons and which point old Galaxy becomes a worthless client that only works essentially offline.

Just uninstall galaxy fully and be done with it, save yourself some disk space, and some headaches.

I have games on it that I play that otherwise don't work. GOG Fallout 3 works unlike Steam ver.

You can still play the games you installed with Galaxy without the Galaxy client. There should be a shortcut in your Start Menu. If not, you can go to the directory that the game is installed in, and double-click the .exe or .bat file that starts the game.

As far as keeping Galaxy from updating, not sure if the /runWithoutUpdating argument works (never tried it before). I know you can run the client's .exe file with anything after it (even /asdjfekla) and it will still load up Galaxy without any messages. To be on the safe side, I went ahead and added it, and also blocked incoming/outgoing connections for the update .exes that I found. Whether that actually blocks anything or not, I don't know that either.

Really this should be in the Galaxy 2.0 Forum. Here's the answer to your questions if you don't want to make the switch:
https://www.gog.com/forum/general_beta_gog_galaxy_2.0/will_galaxy_20_completely_replace_12/post4

https://www.gog.com/forum/general_beta_gog_galaxy_2.0/will_galaxy_20_completely_replace_12/post6

Are you responding to me? If so, you do not need the client for any game here other than gwent. Go to the website, hover over your username and select games. Select a game and hidden under download offline installers are the actual installer files, which you can download, install without galaxy (mostly), and store, put on cd, do whatever you want with. That is the point of this website. Drm free installers which once you have them you own them.

This doesn't actually seem to work.

You need to disable the autostart option from within Galaxy. Close Galaxy, then create a shortcut in your Startup folder to Galaxy with the argument, and then start it from that shortcut. Afterwards, every time your system boots, it'll use that shortcut with the argument.

Not saying anything that hasn't already been done. i've never had it autostart, and always started it from a desktop shortcut that's had that command argument on it since I found out about it. No dice. I'll just be done with their damn launcher if they insist on this cluster.

Same here. Never had the client auto-start and used the /runWithoutUpdating command, but Galaxy still forced the update. It'll let you defer it once by clicking "update later" but the next time you start up the client, it'll force the update on you.

Not sure what's different on mine system then other than maybe the firewall additions. I never had a message asking me if I wanted to update, and I still have 1.2.

It doesn’t ask. It just does it.

What someone else found was deleteing c:programdata/gog.com/galaxy/redists/galaxyupdater

I'm digging into this more on my primary gaming computer. Still 1.2 fortunately on this one (since I haven't rebooted yet), but my laptop forcibly "upgraded" (Because it's not an upgrade in any meaningful way -- it's 100% worse than 1.2. Seriously, there's not a single improvement and there are a pile of things worse.)