problems: GLW_StartOpenGL() - could not load OpenGL subsystem

restart pc? old vid card? take bake your old autoexec xD

r_mode too high

i kept having that once, rebooted then it was fine

Driver issue, iam quite sure.
Update all your drivers

1. Your vid card runned into error/you closed wrong file @ task manager etc, fix = reboot.
2. Too high resolution, fix = lower it in your config, r_mode/r_customweight+r_customheight and look your max. resolution screen settings. :>
3. You don't even have vid card driver, fix = No et for you.

just update your graphic card drivers.........

Update gfx driver and reboot