Due to an unidentified bug in UTDCv21, Windows Vista users are having some problems playing online while using OpenGL.
In most cases these users will either see a crash or a lockup (the screen freezes) after every mapswitch.

The recommended solution is to use Direct3D instead. To switch to Direct3D, please perform the following steps:

1) Go to http://cwdohnal.home.mindspring.com/utglr/ and download the latest Direct3D renderer. The current versions are:
* Direct3D 9.0 Renderer v1.1 - http://cwdohnal.home.mindspring.com/utglr/utd3d9r11.zip
* Direct3D 8.0 Renderer v1.4 - http://cwdohnal.home.mindspring.com/utglr/utd3d8r14.zip

If your graphics card is really old (5+ years), the 8.0 renderer is the best choice.

2) Unzip the file you just downloaded into your UT\System folder.

3) Open your UnrealTournament.ini file which can be found in the UT\System folder.

4) Go to the [Engine.Engine] section in this file and look for the line that starts with GameRenderDevice=

5) Change this line to:
* GameRenderDevice=D3D9Drv.D3D9RenderDevice ; if you've downloaded the 9.0 renderer
* GameRenderDevice=D3D8Drv.D3D8RenderDevice ; if you've downloaded the 8.0 renderer

6) Now go to the end of the UnrealTournament.ini file and add these lines (copy paste them):

[D3D8Drv.D3D8RenderDevice]
SwapInterval=0
ZRangeHack=False
NoAATiles=False
NumAASamples=0
UseAA=False
RequestHighResolutionZ=True
UseSoftwareVertexProcessing=False
UsePureDevice=True
UseTripleBuffering=False
MaskedTextureHack=False
SmoothMaskedTextures=False
FrameRateLimit=85
UseVertexProgram=True
TexDXT1ToDXT3=False
DynamicTexIdRecycleLevel=100
CacheStaticMaps=False
UseTexPool=True
UseTexIdPool=True
UseSSE2=True
UseSSE=True
BufferTileQuads=True
BufferClippedActorTris=True
SinglePassDetail=False
SinglePassFog=False
ColorizeDetailTextures=False
DetailClipping=False
UseDetailAlpha=True
DetailMax=0
RefreshRate=0
MaxTMUnits=0
NoFiltering=False
MaxAnisotropy=0
Use565Textures=False
Use16BitTextures=False
UseS3TC=False
UseAlphaPalette=False
UseTrilinear=False
UsePrecache=False
UsePalette=False
UseMultiTexture=True
MaxLogTextureSize=8
MinLogTextureSize=0
MaxLogVOverU=8
MaxLogUOverV=8
OneXBlending=True
GammaCorrectScreenshots=False
GammaOffsetBlue=0.000000
GammaOffsetGreen=0.000000
GammaOffsetRed=0.000000
GammaOffset=0.100000
LODBias=0.000000
DetailTextures=False
DescFlags=0
Description=
HighDetailActors=False
Coronas=False
ShinySurfaces=False
VolumetricLighting=False

[D3D9Drv.D3D9RenderDevice]
SwapInterval=0
ZRangeHack=False
NoAATiles=False
NumAASamples=0
UseAA=False
RequestHighResolutionZ=True
UseSoftwareVertexProcessing=False
UsePureDevice=True
UseTripleBuffering=False
MaskedTextureHack=False
SmoothMaskedTextures=False
FrameRateLimit=85
UseVertexProgram=True
TexDXT1ToDXT3=False
DynamicTexIdRecycleLevel=100
CacheStaticMaps=False
UseTexPool=True
UseTexIdPool=True
UseSSE2=True
UseSSE=True
BufferTileQuads=True
BufferClippedActorTris=True
SinglePassDetail=False
SinglePassFog=False
ColorizeDetailTextures=False
DetailClipping=False
UseDetailAlpha=True
DetailMax=0
RefreshRate=0
MaxTMUnits=0
NoFiltering=False
MaxAnisotropy=0
Use565Textures=False
Use16BitTextures=False
UseS3TC=False
UseAlphaPalette=False
UseTrilinear=False
UsePrecache=False
UsePalette=False
UseMultiTexture=True
MaxLogTextureSize=8
MinLogTextureSize=0
MaxLogVOverU=8
MaxLogUOverV=8
OneXBlending=True
GammaCorrectScreenshots=False
GammaOffsetBlue=0.000000
GammaOffsetGreen=0.000000
GammaOffsetRed=0.000000
GammaOffset=0.100000
LODBias=0.000000
DetailTextures=False
DescFlags=0
Description=
HighDetailActors=False
Coronas=False
ShinySurfaces=False
VolumetricLighting=False

7) Now save the UnrealTournament.ini file and restart UT.

The look and feel of your UT should now be almost the same as with OpenGL (but without the crashes!).

-- AnthraX