Vista Ultimate 64x does not detect 4 gb RAM RRS feed

  • Question

  • I have installed a 64 bit Windows Vista Ultimate and 32 bit Vista Home Premium on the same machine. Strangely, my 64 bit version only detects 3.2 gb Ram. I expect my 32 bit version to do that, but 64 bit should be able to detect full 4 gb. Can you please help me what to do??
    Saturday, November 3, 2007 7:06 PM


All replies

  • Hello Lior,


    Based on my research, if some memory related features provided by hardware manufacturers are enabled, the problem you described may occur. you may contact the manufacturer of your PC to confirm that.


    I list some links for reference:


    1.     For ProLiant DL580 And ProLiant ML570:

    2.     For Dell PowerEdge 1850, PowerEdge 2800 and PowerEdge 2850 servers:

    3.     For some IBM machines:

    Important Note: This response contains a reference to a third party World Wide Web site. Microsoft is providing this information as a convenience to you. Microsoft does not control these sites and has not tested any software or information found on these sites; therefore, Microsoft cannot make any representations regarding the quality, safety, or suitability of any software or information found there. There are inherent dangers in the use of any software found on the Internet, and Microsoft cautions you to make sure that you completely understand the risk before retrieving any software from the Internet.



    Lionel Chen


    Monday, November 5, 2007 11:04 AM
  • I also have vista home premium 64x but i have installed 6 gigs.. 2x1g and 2x2g.  Windows reads only 4 gigs. i hear people having problems with 4 gigs reading 3, what's up with windows reading only 4 when i have 6?


    please help


    Wednesday, November 28, 2007 3:42 AM
  • Hello,


    Thanks for your post!


    Please check whether BIOS can read the correct size of RAM. If it can’t:

    1.    Mixed memory sticks with different sizes, types (voltage, interface, etc.) or models very possibly cause such issues.

    2.    Update the driver of BIOS, in case the legacy version of BIOS may have limit of RAM display.

    3.    Check the memory sticks, confirm none of them is damaged.

    If only the system can’t recognize some of the RAM:

    1.    Supposing the 2 sticks of RAM are exactly the same, please remove the two sticks of 1G RAM, and check the display. If it correctly show 4GB, the problem may be caused by the first possibility listed above.

    2.    If it shows less than 4 GB, for example 2 or 3 GB, please make sure whether there are some devices (especially intergraded video card) that occupy some RAM; Please there may be some built-in features of motherboard that will hide some RAM.

    I hope the issue can be fixed soon!



    Lionel Chen

    Microsoft Online Community Support

    Wednesday, November 28, 2007 9:47 AM