I have the same. 32 bit vista which should be able to use 4gb according to the blurb.
On mine in system maintenance of welcome center it shows 2.75gb
On system info properties of (my)computer it shows 2814mb
In the bios and running memtest86 it shows and tests 4gb
I am using a BFG 680i m/board and ocz ddr2 8500 ram.
the answer is no and it could but it does not....the 32 bit has its limitation....for example, I have installed 4GB of memory and it reads only 3.325.....When my 64 bit DVD drivers arrive and I install them I should get a full 4.0GB reading......