I tried to install it through the installer on the main page but it gets to half way through the download and halts completely
I left it half an hour but it was still where it was before so I closed it and found an offline installer in an old forum post
Now this offline installer is 2.0.16.182 which seems to be quite out of date

It installs fine but I can't check for updates or get it to auto-update or anything like that
There's a post on here from two days ago with a link to a later version but I get an "Access to gog-dc-lumen.secure2.footprint.net was denied" error
If I right click the link and attempt to save as I get a "File wasn't available on site" error in the browser

Any ideas how I get the latest version?


EDIT: also I tried to access this webpage support.gog.com/hc/en-us/sections/360004686293-GOG-GALAXY-2-0?product=gog but I get an "Oops, you're not authorised to access this page" error when viewing it so if there's handy info on there that'll solve my problem can someone copy-paste in please?

Here you go:

https://cdn.gog.com/open/galaxy/client/2.0.75.142/setup_galaxy_2.0.75.142.exe

Perfect! Legend, thank you!