DOS Games made for DOS require an emulator to run on Windows. Use DOSBox or a frontend like D-Fend Reloaded and read this guide to play DOS games on your Windows PC.
Space Quest was remade using Sierra's newer SCI game engine, which allowed the game to move from its original 16-color EGA graphics to 256-color VGA. Rebranded Space Quest I: Roger Wilco in the Sarien Encounter , this version was released on August 20, 1991.
The above text is licensed under the GNU Free Documentation License. This text is based on this Wikipedia article.
Search on eBay