Follow these instructions:
- Download the game: Dungeon Master II for Sega CD / Mega CD
- Download this Sega CD emulator for Windows: Gens.
- Download a Sega CD BIOS image. Go to BIOS Images at The Old Computer Dot Com to download the Sega Mega CD BIOS image file (American Sega CD model 2 BIOS Version 2.00, June 1993).
- Uncompress the game (both the ISO and the MP3 files), the emulator, the BIOS image, and put them all in the same folder on your hard disk.
- Run GENS.EXE. Go to the "Options" menu, and click on "Directories/Files". In the "Configure SEGA CD bios files" section, click the "Change" button on the USA line, and select the file "US_SCD2_9306.BIN". Click "Save" and then "OK".
- In the "File" menu, click "Open ROM", select "Dungeon Master II - Skullkeep.iso" and click "Open".
- Check the "GENS.TXT" file for default control keys, or go to "Options/Joypads..." to redefine keys.