HELP! 4GB RAM Recognized as 3.5GB! Please read.... RRS feed

  • Question

  • Hello to all!
    To begin with, I should tell you my system:
    m/b having Intel P965 chipset
    CPU Intel Core 2 Duo 1066FSB @ 2.4Ghz
    RAM DDR2 @ 800 Mhz
    32-bit Operating Systems (Vista Ultimate & XP Professional)

    I've just installed 2 new DIMMS of 2GB each at dual channel mode
    When I switch on my computer, bios recognizes FULL Ram, 4,126,000 MB (appr.)
    Both Windows Vista & XP recognizes 3,5GB of ram!

    Is anything possible to do, in order to make my OS to recognize FULL capacity of RA (4GB)?

    If I install a x64 OS, will I have all the capacity available?


    Sunday, February 24, 2008 10:40 AM


  • Hello,


    Based on my experience, there are 3 major possibilities that may cause this issue:


    1.    PAE is not enabled. Please refer to the following KB article for more information:

    (KB929580) Windows Vista or Windows Server 2003 may report less memory than you expect

    2.    Some built-in features or integrated chipset may (video card, usually) occupy some memory.

    3.    Some motherboards don’t correctly support dual-boot and lead to memory incorrect display.

    If this issue is only due to Cause 1, upgrading to 64-bit edition or enabling PAE could both fix it.



    Lionel Chen

    Microsoft Online Community Support


    Wednesday, February 27, 2008 9:32 AM