My PC was working for a few hours and I heard my CPU fan all the time but after a few hours it started to become very strange so I opened Task Manager and noticed that the launcher is consuming 20% of CPU.

Why?

Edit: I have attached picture but I do not see it.

Is GOG installing a game/update in the background? Without knowing what your CPU is, it's difficult to tell if 20% usage is particularly strange. As an example, on very old CPUs, Steam can use ~50% of your CPU.

Pic is prolly too big, limit is 500 kB (yes kB, not MB) per pic, 2 MB total

I came here for 400% insane and found 20% insane. My disappointment is immeasurable :P.

Have you tried turning it off and on again? I'm being serious. If you close Galaxy and are sure all the background processes are terminated, and then start it again, does it return to 20% usage?

Also I have no clue what your specs are, so I have no idea how much "20%" is supposed to mean. If you have a potato PC, 20% could be expected.

You can significantly reduce CPU utilization and power consumption of a running process by utilizing Task Manager Efficiency Mode

Thanks for pointing it out! The feature itself is available in Windows 10 and 11, but the names are different. In Windows 10, it is called Eco Mode and in Windows 11, it's called Efficiency Mode.

https://www.tenforums.com/tutorials/178076-how-enable-disable-eco-mode-app-process-windows-10-a.html
Starting with Windows 10 build 21387, Microsoft turned off the “Eco mode” feature in Task Manager in order to refine the experience and address several issues thanks to Windows Insider feedback.

Looks like ECO mode was once in an insider build of W10, and then removed.

This reminds me of a Virus I once had, which always activated something that used up pretty much all my CPU whenever I was idle (including simply watching Youtube, so the videos just started freezing out of nowhere) and deactivated it the second I used any input.
I tried deleting certain files and everything, even in Offline mode and so on and so on, but I was never able to get rid of it fully, so sadly I had to put my PC back to factory mode and do everything from the start up.

I hope you don't have this.

Oh, that's unfortunate.

I like that feature because it keeps FF and some other apps in check, without negatively impacting their performance.