So, you’re note able to play DF1 Singleplayer ?
This means normally that the game can’t find the CD.
It NEEDS to be in the same drive where you installed the game from. This setting is stored in DF.CD, as shown in the picture below.

This file is a textfile, and only contains the drive-letter it expects the CD in. you can edit this by hand. If you’re missing this file, try reinstalling the game. You MIGHT want to try this file to see if it works for you. Don’t forget to edit it with notepad so it reflects the proper drive !

You’re welcome.

NedFox <TZW>