you need a 64-bit operating system to utilize 4 gbs of ram.
most ppl only have a 32-bit operating system which will only recognize 3.x amount of ram.
It's DETECTING all 4GB, it's not using the .75GB...
32BIT - 3.25GB Max
64BIT - 128GB Max
But XP x64, regret it later. I'd shoot for Vista on this occasion. Too many hassles with drivers...
There is the problem, all the sticks work, I just tried them, so can I upgrade to XP 64 and it will work?
And how much is XP 64?
Or is it USING all 4 gb, just not SHOWING that it is?