Windows 7: adding memory results in less usable memory

i have a new HP Z400 workstation. it has a new install of windows 7 enterprise 64bit with all updates. the pc came with 6gb of ram installed. i purchased 6gb of kingston memory that was specifically listed for this workstation. the ram is installed as 6 x 2gb modules. slot 1 factory module slot 2 kingston module slot 3 factory module slot 4 kingston module slot 5 factory module slot 6 kingston module. when this pc just had the factory modules it shows 6 gb installed 5.83 usable. it now shows 12gb installed with only 3.23 usable. what is causing the decrease in usable memory as well as what is causing the usable memory to be a fraction of the installed memory?

Welcome
First reseat the ram sticks.
I would change locations of the sticks too
If still have the problem, take Ram Test
Download memtest86 and test RAM
www.sevenforums.com/tutorials/105647-ram-test-memtest86.html
Run for 6 passes/

It could also be mix and match a no, no.

as rich said, first try reseating the modules.. that was a huge issue for me. easy to solve tho if that is what is wrong.

next run memtest 86 to ensure that the hardware is good and in working order

then if all the hardware is good, I would consult your user manual to be sure that the paired sticks are in the correct memory slots.

HP is working on a bios revision. the bios revision in the pc (which is the current revision) has issues with memory addressing. that said there is a workaround to getting usable memory to be consistent with installed memory. it involves the msconfig file (I did not run any memtests. all of the memory modules are fine).

a simple, and painless, way to force windows to recognize correct usable memory is open msconfig by entering msconfig in a run command. go to the boot tab click advanced. uncheck maximum memory, reboot, open msconfig and check maximum memory, reboot.

this may not work for everyone but worked for me

im glad you got your issue resolved.


that statement makes me cringe, if only for the fact that i went through bad memory problems a month ago...