The zip file has the required directory structure, so it's best to extract it on the desktop restoring the folder structure. Place an IWAD (the main game file) in the same folder as gfDoom.exe.
For more information on the skins, read 'Skin Specs.txt'
WHAT IS A WAD?
A wad file is required to play gfDoom. These are the level and other data of the game. This is seperate from the Doom executable program file in the zip.
By doing this iD software have been able to keep Doom as commercial software and release the source code.
A shareware wad file can be found freely on the internet.
You may have commercial version of Doom. If so, copy the .wad file to the device. This way you will be able to play all the Doom levels.
Name your IWAD:
gfDoom recognises the type of IWAD that is being used by it's name. (It also checks for sharware versions disguised as registered wads!)
Call the IWAD:
Doom1.wad ->Shareware version.
Doom.wad ->Registered version. 3 episodes.
Doomu.wad ->Ultimate Doom. 4 Episodes.
Doom2.wad ->DoomII.
Plutonia.wad ->Plutonia exp.
tnt.wad ->TnT.
Put this IWAD in the same directory as gfDoom.exe
gfDOOM LAUNCHER:
Just a quick utility I knocked out to test PWADS and skins. Keep it in the same folder as gfDoom.exe and use it to load PWADS, Skins and select from multiple IWADS.
Put PWADS in the same folder as gfDoom.exe, the launcher will find them automatically.