I get E_OUTOFMEMORY with any Nvidia card and Detonator XP (version 21.81)! What is wrong?
It seems that the version 21.81 drivers don’t release the used memory in some occasions. As this seems to be a driver issue, you can try to install some of the older drivers (Detonator3 v12.41 or older) which seem to work fine, or download newer official drivers version 21.83 (Click here to download) which should fix the problem. There is also another workaround for this issue. Go to your Display Properties, select Settings -> Advanced -> Your gfx card tab -> Additional Properties -> Direct3D Settings, and from there set the PCI Texture Memory Size to zero (0).