Hello!, Microsoft says at: https://www.microsoft.com/whdc/system/platform/server/pae/paemem.mspx Windows XP Professional and Windows Server 2003 Memory Support. The maximum amount of memory that can be supported on Windows XP Professional and Windows Server 2003 is also 4 GB. However, Windows Server 2003, Enterprise Edition supports 32 GB of physical RAM and Windows Server 2003, Datacenter Edition supports 64 GB of physical RAM using the PAE feature. I use two Acer Aspire Notebook: 1 - A5920G 2 - A6920G Both work in multiboot, with Windows Vista, XP and Ubuntu. Vista is installed in the 2nd primary partition of 30 GB (the first primary is inaccessible because code 27, for Recovery use). Windows XP Professional SP3 is installed in the 3rd primary partition of 20 GB. Ubuntu is installed in extended, and the Data partitions also, as logical partitions. The laptops have each of one 3 GB of RAM (native original), 1x2 GB + 1x1 GB. Vista recognizes and uses 3 GB of RAM, in both laptops. Ubuntu recognizes and uses 3 GB of RAM, in both laptops. XP Professional otherwise recognizes and uses only 768 MB (512 MB + 256 MB), in both laptops. The drivers for XP were downloaded from ACER Support Web site, properly for the specified laptops. When I boot the laptops by HBCD (Hiren's Boot CD) v11.0, Windows XP SP3 in Virtual Mode recognizes 3 GB of RAM. How can I force the installed Windows XP to recognize the whole RAM of 3 GB? Please, Mr. RHochstenbach, read well! Regards.
