Hello. Galaxy doesn't start automatically when my computer boot despite checking the tickbox. To fix this, I want to uninstall, reinstall, and see if it works right. However, I can't find the uninstaller in the Galaxy folder. Help, please?

Maybe try using Revo Uninstaller?

https://www.revouninstaller.com/

Just gave it a try at your suggestion, Revo doesn't seem to detect Galaxy.

Why not just use the Windows uninstaller?

If you're using Windows 10, go to the Start Menu, Right Click on the GOG application icon, select Uninstall. From the list that pops up, select GOG to Uninstall. Follow the prompts.

Does this help?

https://www.gog.com/forum/general/anyone_know_how_to_uninstall_gog_galaxy/?search=uninstall%20galaxy

It takes you to a specific thread, just not a general search ,)

It shows up in my start menu but not my app list.

That's very strange. Try reinstalling on top of it. Maybe the uninstallation registry keys weren't implemented.

Very strange, have you tried contacting technical support?

are you using windows 10?
try right clicking it in the start menu and see if there's an uninstall option?
(scroll down the start menu, don't right click on the shortcuts elsewhere)

edit: actually it looks like you can uninstall from the live tiles in the start menu. not tried specifically with GoG Galaxy, but maybe give it a try?

In General, a very strange situation, indeed, some users simply do not find the uninstaller from Galaxy. Have you tried contacting technical support?
Usually I use third-party programs in such situations, which can easily cope with such problems. They track installed files and clean up residual ones after deletion. Third-party programs are best uninstallers, compared to the standard Windows Uninstaller, it can't always detect files.