I moved your post over to Glitches.
A search on the GOG forum reveals that other people have had this problem, too, and that it can occur randomly. I found this thread
here. I also found
this on the GOG Support pages.
And this from a Wikia page:
The game requires a CD drive to play, even if you are playing the GoG.com version. This causes a problem with computers, laptops, or netbooks with no cd drives. To get past this problem you will need to use a virtual drive such as daemontools to trick the software into loading. Or use the installer on Sierrahelp.
If all else fails, I would write to GOG Customer Support, as they might have an additional workaround.
acebook
witter
