Ok -- I fixed my prob so I decided to create a guide because a large number of people have complained about this:
Ok, so you are trying to run tremulous in Vista and it gives you a OpenGL subsystem cannot load error. Heres how to fix it:
Step 1: Go into "C:\Users\<username>\AppData\Local\Tremulous\base" (hidden folders have to be shown) and open autogen.cfg in notepad or any plain text editor.
Step 2: Look for this line: seta r_mode "9" and replace it with seta r_mode "3". (it might not be exactly 9 but replace it anyways)
Now when you start trem (it should start now) it should look like this:
.
Step 3 (unneeded if trem is in full screen and does not look like the above picture): Click Play then join any server. After you have joined press "Escape" (top left of your keyboard) and select Options then System. Then click on the resolution (the thing that looks like 1200x780) and change it from like 350x 250 to atleast like 1100x700. It should look normal now and start normal. You might have noticed that the "r_mode" variable has changed since you played the game. Thats normal.
