I have a new HP Z800 Workstation, running Windows 7 Enterprise 64 bit. Z800 Specs are here.
The machine has 4GB of RAM — windows reported 1.99GB available, 2GB was "hardware reserved". I added another 2 GB and windows reports that there is 6GB of physical RAM, but now 4GB is "hardware reserved". The BIOS sees the full RAM amount as well.
The video card is an nVidia Quadro FX 580, so it shouldn't be using any shared memory at all.
Why is all my extra RAM marked as "hardware reserved" in Windows 7?
Best Answer
Turns out that the installed RAM was in an unsupported config -- On this machine, if you install 2GB chips, they have to be installed in triple, as referenced here (pdf).
Its interesting to note that Windows saw the memory, but it was rendered not usable and marked as "hardware reserved".