hey man, did u try updating ur bios. u use 2x 2gb ram , right ? u said that when installed an additional 2gb , this issue arises. Now try the 2nd 2gb alone ?. check it.. dvmt is dynamic video memory technology. I think it has nothing to do with ur issue..
if ur bios is up to date, try removing ur gfx card and see how much ram bios shows with ur onboard VGA. check it and tell me mate...
all guys FYI , XP has a limitation of 3GB memory. But the OS has nothing to do with the bios. BIOS SHOULD report the full memory.
all these limitations are immaterial for the BIOS.
axeman, u r wrong. I am using 2x2gb ram and i am able to utilise the full 4GB in my OS which is Vista 32bit SP1.
Its not necessary to have x64 OS to utilise full 4gb, even 32bit vista can do it....