Microsoft W840DI - Manual (Page 38)

Memory User's Guide
3.1 Limitation Of 32-bit Windows™ OS
Below description applies to 32-bit Windows™ OS only, unless otherwise specified. 32-bit
Windows™ OS is confined to the limitation of 4GB (2
32-1 ) of addressable memory space.
This would not be an issue when you use Windows™ to view the system memory. That is
when you have installed 4GB memory as listed above, Windows™ would report the system
memory to be 4GB.
However, if you use other application programs, the reported “available memory size” can
be somewhat smaller than the total amount of memory you have installed. When this
situation occurs, the reported system memory is overlapped by the video memory and
appeared to roughly equal to 4GB minus the total video memory taken up by the video
memory of VGA cards. Your system supports single and dual VGA card configurations. So
the amount of overlapping really depends on the quantity and the size of video memory you
have installed in the system.
There is no such limitation in 64-bit Windows™ OS.
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