For once, I decided to buy a game. Quake 4 was only €15 so I said "heck, why not". I installed it, updated to the latest version but I can't make it use High Quality textures. No matter what I do, the game is stuck in Low Settings, just like in the picture. I have tried tweaking the .cfg file to no avail. Is there anything I can do to solve this problem? I'm using:

P4HT@3.06GHz
2GB RAM
nVidia GeForce 8600GT 256MB DDR3
Windows XP SP3