We’d like to inform you that we have an update regarding your problem.

The following link contains an updated GOG GALAXY version that will:
- Fix a bug where GOG GALAXY failed to launch or update on Windows 8.1 and Windows 7
- Fix a bug where GOG GALAXY failed to launch, claiming it was already running on another account
- Opt you into GOG GALAXY "public beta" updates

https://content-system.gog.com/open_link/download?path=/open/galaxy/client/2.0.42.21/setup_galaxy_BETA_2.0.42.21.exe

What that means is that you’ll be getting updates with the newest features and patches that we’ll be releasing to the users. You have the possibility to opt out by disabling this setting yourself in the app settings (“public beta” checkbox), however we recommend that you refrain from doing so until the next GOG GALAXY update, that will contain the fixes included in this patch.
If you are still on Windows 7 we recommend that you update to the newest version of Windows as the client will stop working on this OS one day.

Please respond and let us know whether Your problem has been resolved! :)