Minimum requirements: Vanilla DOOM (MS-DOS or PrBoom+), or GZDOOM
After you install it, extract the zip file (any zip file manager, recommended 7-zip), then put it into the DOOM source port's directory (like d:\games\DOOM\Source Ports\Prboom-plus-2.5.1.4). Drag the wad file to its executable and you are good to go. Alternatively, use the command prompt, go to the DOOM source port directory (example, d:\games\DOOM\Source Ports\Prboom-plus-2.5.1.4), then type this in the command prompt:
DOOMSOURCEPORT.exe -iwad doom.wad -file e1m1mem.wad - then enter.
