3 gigs of ram but vista only shows 2

[bufodr_T]

Hi all. I just installed vista home premium on my pc. i have 2 1 gig sticks dual channel and 2 512 gig sticks dual channel. The memory shows up in cpuz as 3gb, but vista system properties only shows 2045MB. Whats up with this. Anyone else have this problem>
THanks