HKEY_LOCAL_MACHINE\Software\LucasArts Entertainment Company\JediKnight\v1.0
Replace the music tracks with higher quality ones ripped from the original CD.
Make the game always use the highest quality textures and models, instead of using lower qualities the further away they are (and leading to unsightly transitions).
DIBsection windowed display
Windows XP (Service Pack 3)
Running the game with 3D acceleration turned on may cause crashes or graphics problems (ex. black screens) on some modern machines.
Download and extract this ddraw.dll to the installation folder. If that one doesn't work, try this one.
This issue is present in the original CD release and may also apply to releases patched with the Unofficial Patch.
Run the game with the -windowgui command line parameter.
The game updates camera movement at only 30 FPS, even though the game runs at 60 FPS. This gives the appearance of poor performance and can be improved by capping the framerate below 48.
Press - or = to adjust the screen size.
Rename JK.exe to something else, like JediKnight.exe. You could also download the fixed music wrapper, use a text editor to read and follow the instructions at the top of the single .reg file and then double-click on the file to import it. You can ignore the other files in the archive.
If the game crashes with an Nvidia GPU, disable the following settings for JK.exe in the Nvidia control panel: