Mindz ...
gfx.wad error means it cannot find the pak files ...
Your Quake folder ...
Should have joequake.exe and joequakegl.exe in there, plus dzip.exe and some .dll file not pictured in the screenshot.
Your Quake/JoeQuake folder ...
Should have your config.cfg that you manually copy into there from quake\id1.
Your NORMAL pak0.pak and pak1.pak should be in the quake/id1 folder right below the folder where JoeQuake.exe and JoeQuakeGL.exe is in.
The pak0.pak that comes with JoeQuake should be in quake/joequake and should not overwrite your existing pak0.pak that is in id1.
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