I have installed two 2GB-RAM modules in a motherboard, but its BIOS only recognize 2GB total. I have tried to boot up with only one of the 2GB-RAM modules, and then the BIOS only recognize 1GB.
The motherboard (Asus P5QL Pro) supports up to 4 x DIMM, Max. 16 GB, DDR2 1066/800/667.
And the DIMM's I'm installing are "Kingston HyperX 4 GB DDR2 1066 kit KHX8500D2K2/4G CL5 5-5-15" (i.e. two modules of 2GB each).
Taking into account the tests I've done, it seems the system always recognize the half of the RAM I install (it recognize 1GB when installed one module and 2GB when installed two modules).
My first though was "Huh? I've bought 1GB modules instead of buying 2GB modules", but actually, that kit has 4GB total, hasn't it?
I would understand WinXP didn't recognize the 4GB, because it reserved some spare memory for the graphic card, but I supose the BIOS should actually recognize all the memory I install.
If anyone has any clue on how to solve this, I would thank him/her.
I did install them in the same colour slots, but I've already solved the problem. It was an error from the vendor: the container box stated "Kingston HyperX 4 GB DDR2 1066 kit KHX8500D2K2/4G CL5 5-5-15"; each module is labeled as "KHX8500D2/1G" though. So I really have 2 x 1GB modules, instead of 2 x 2GB modules.