Urban terror

Bonjour,
Quand je veux ouvrir urban terror il me met ça:
...hardware acceleration found
...PIXELFORMAT 9 selected
...creating GL context: succeeded
...making context current: succeeded
...WARNING: fullscreen unavailable in this mode
...setting mode 8: 1280 1024 FS
...using colorsbits of 16
...calling CDS: failed, bad mode
...trying next higher resolution: failed, bad mode
...restoring display settings
...window already present, CreateWindowEx skipped
Initializing OpenGL driver
...WARNING: fullscreen unavailable in this mode
...shutting down QGL
...unloading OpenGL DLL
...assuming '3dfxvgl' is a standalone driver
...initializing QGL
...WARNING: missing Glide installation, assuming no 3Dfx available
...shutting down QGL
----- CL_Shutdown -----
RE_Shutdown( 1 )
-----------------------
GLW_StartOpenGL() - could not load OpenGL subsystem

Et il ne veut pas s'ouvrir a cause de ça GLW_StartOpenGL() - could not load OpenGL subsystem et de la résolution qui est trop importante je crois (...WARNING: fullscreen unavailable in this mode
...setting mode 8: 1280 1024 FS)
donc comment faire pour baisser la résolution sans aller sur le jeu.
merci