When I launch the game, it launches, but a piece of the previous screen(or the desktop, in case all the screens are closed)
, stays stuck and does not disappear. The game works, but that piece stays there...

Thanks for your help:)

What game...?

Through galaxy?

Try closing every window, including galaxy, and start the game directly from its directory.

Runaway: A road adventure I did it, it still stuck with that piece

Try reboot.

Why didn't you write that in the first place?! :P

;)

it worked good in the past on a computer, but now on laptop windows 10, it does that..

Try run as admin.

Uninstall, delete config folder(s) and reinstall (offline installers).

Don't know the game but if it persist then GOG support might have the answer.

EDIT: Yes, the infamous Win 10...

yes already sent a message, but I hope you guys will be faster;)

Try right clicking the Runaway.exe
properties > compatibility > Disable display scaling on high DPI settings (or Override high DPI scaling behavior.)

EDIT: perhaps try other options on the compatibility tab and/or run as under windows xp or win9x.