Hi!
when i launch the game trough gog galaxy it does not starts, just a black square in the middle of the screen. when i double click in the desktop icon a message appears saying:
witcher3.exe - No Disk
There is no disk in the drive. Please insert a disk into drive D:.

How can i fix this problem?
Please help!

Did you install the game from an external disk? Also, do you have other peripherals (card readers etc.) attached?

i install the game by downloading the intall files from gog. i have a usb 3.0 spliter / card reader in wich i attach my razor mouse, is that a problem?

Not a problem. I was just thinking what could make the game check for external drives. Try populating the card reader and see if that makes a difference. It's a long shot, but you have nothing to lose by trying.