This device cannot find enough free resources that it can use. Code 12

I spent quite some time figuring out a particular problem I was having, and figured I would share some tips as they were not readily available on the web. (At least not where I could find them...)

The problem: I have an ASUS P5W DH Deluxe motherboard with 2x1GB RAM. I'm running Windows Vista 32bits Business. After installing an extra pair of 512MB chips (Kingston KVR800D2N5K2/1G kit) next to the already existing 2GB kit (Kingston KVR800D2N5K2/2G) my PC would no longer recognize my Nvidia GeForce 8800 GTS graphics card. In device manager the 'Intel(R) 975X PCI Express Root Port - 277D' showed a yellow exclamation mark, and looking at the detailed info gave a 'This device cannot find enough free resources that it can use. (Code 12)' error message. The system fell back to lo-res VGA mode.

What didn't work: Trying to remove and re-install drivers. Moving cards to another slot on the motherboard. Changing all kinds of settings in the BIOS. Pulling out hair. Screaming...

The solution: When visiting the ASUS support site I noticed that one of the BIOS updates mentioned 'Enhance memory compatibility'. I downloaded the most recent BIOS for my motherboard, used the ASUS update utility to flash the new BIOS and hey presto, the problem was gone. I did have to re-enter several BIOS settings before the PC would properly boot of course, so make sure you write down all BIOS settings before you flash.

I hope this info will help people running into the same problem.