"Open UT2003.ini and search for the [WinDrv.WindowsClient] line and change the settings below it to these :
ScreenFlashes=False
TextureDetailInterface=UltraHigh
TextureDetailTerrain=UltraHigh
TextureDetailWeaponSkin=UltraHigh
TextureDetailPlayerSkin=UltraHigh
TextureDetailWorld=UltraHigh
TextureDetailRenderMap=UltraHigh
TextureDetailLightmap=UltraHigh
Under the [D3DDrv.D3DRenderDevice] line:
UseVSync=True
These are the only options you should have to tweak. Your computer will detect the rest of the settings and set them accordingly if you have a machine fast enough to run with high detail. But here is a list of features that you could theoretically bump up to the max for highest quality image detail (screw framerates, you want to see this game at this best)
[WinDrv.WindowsClient]
MinDesiredFrameRate=0.000000
[D3DDrv.D3DRenderDevice]
DetailTextures=True
HighDetailActors=True
SuperHighDetailActors=True
UsePrecaching=True
UseTrilinear=True
DesiredRefreshRate=0"
Have fun
