I just updated my computer to be able to run windows 7, 64 bit OS. I also bought more RAM (4 GB more that the 4 GB that was already installed in my old system (DDR2, PC6400 at 800 MHz). However, the MB only sees 4 GB (as I can see in the bios) and the windows 7 off course does not see more either?
I am completely at a loss, and have no idea what to do to make the memory available ( I updated the BIOS already and that did not fix it!). Any help is appreciated!
I don't have a first-hand experience with a situation like this, but I heard that you may have to enable memory remapping in the bios. I don't know if it is called exactly the same on your board, but you may have to look for something like that in the bios.
If you're *sure* you're running the 64 bit version of the OS, from here I see two possibilities. The first is your motherboard may have a limitation - either by design or by BIOS setting. Check your motherboard's support page to verify your motherboard actually supports 4GB of ram or more. Then check your BIOS for a feature called Memory Remapping. If Memory remapping options appear in the BIOS at all, make sure it is turned on.
For the second: Click the Start orb, and type in msconfig. Right click the msconfig app to run it as Administrator. That brings up the configuration utility. Click the Boot tab, and then click the Advanced Options button. In that window, there is a setting for Maximum Memory - Make sure the checkbox for it is clear (not checked), then reboot your computer.
I was having an issue where my 32 gigs of installed memory was only offering 16 gigs usable. This was due to my version of windows 64 bit being the Home version rather than the Ultimate or pro versions which now support 32 gigs of ram. Perhaps this is you issue as well.