I'm running a 64bit system and I've installed the 1.9 patch, DX11 patch, and texture pack in that order. I restarted after each patch to ensure a good install. The DX11 features work but the high res texture button is grayed out. Also on start up the game says it doesn't support HD5800 series cards. I was thinking this may be the problem but am unsure as i don't have another GPUs to test it on. I've looked all over the internet and can't find anything on someone having this problem with a 64bit system.

Specs
XFX HD 5850 running 11.6 drivers
Phenom 9600
MSI K9A2 Platinum V2
4GB DDR800 RAM
Vista 64bit Home Premium SP2

UPDATE:
i launched the game and opened the console and it said that I had 0MB of VRAM available. I'm guessing this is the problem let me know if there are any know fixes for this please.

UPDATE:
i launched the game and opened the console and it said that I had 0MB of VRAM available. I'm guessing this is the problem let me know if there are any know fixes for this please.

How much VRAM does the card have?

AFAIK you need to have a 1GB of VRAM to run the High Res Textures.

I'm using a 5850 with 11.6 drivers and don't have any problems with the high res patch

How much VRAM does the card have?

AFAIK you need to have a 1GB of VRAM to run the High Res Textures.

It's 1GB and i meet all other requirements. I've tried uninstalling the game and reinstalling it with the patches 3 times. I also tried re-downloading the High Res patch from a different source as well.

try this dude!
http://www.gamesas.com/forums/viewtopic.php?f=40&t=34404