Another issue is Windows XP PRO only reports 2.75RAM DDR3 of 2x 2GB
sticks (4GB), Will windows 7 cure this. The comp shop where I got this
system says XP has a limitation and Windows 7 will report all of the
memory attched to my machine and use it properly.
Sorry to tell you, but the people at the computer shop don't know what
they are talking about. It's exactly the same in XP and Windows 7.
Here's the scoop on this:
All 32-bit client versions of Windows (not just XP/Vista/7) have a 4GB
address space (64-bit versions can use much more). That's the
theoretical upper limit beyond which you can not go.
But you can't use the entire address space. Even though you have a
4GB address space, you can only use *around* 3.1GB of RAM. That's
because some of that space is used by hardware and is not available to
the operating system and applications. The amount you can
use varies, depending on what hardware you have installed, but can
range from as little as 2GB to as much as 3.5GB. It's usually around
3.1GB.
Note that the hardware is using the address *space*, not the actual
RAM itself. If you have a greater amount of RAM, the rest of the RAM
goes unused because there is no address space to map it to.