Windows 7: Only 3.5GB Ram? Wait I have 4!

Hi guys, I took an older system of mine... an AMD 3200+ x64 @2.42GHZ, a GA-K8U-939 Gigabyte Mobo, 4GB Ram. I did a fresh instal of 7 x64 Ult. and it still reads 3.5GB ram. I know that XP 32bit had an issue with Ram maxing out @ 3.5GB but from experience i understand Vista and 7 (esp. the 64bit versions) would take care of that... after all, both my other computers wee upgraded much the same way and ALL tthe RAM is visible and useable.
I went on the Gigabyte website to maybe get a BIOS upgrade but everytime I use Face or easybios, I get a message that the BIOS is NOT for my operating system and yes, I do choose the Windows 7 64 bit option. i sent out an e-mail to gigabyte 2 days ago and still have no response from them.
What to do? Any ideas?
Your help is much appreciated.
Regards...

Take the memory diagnostic test
Go to task manager and make sure all your ram is being utilized.

Is your 3.5 available or total?

Have you the latest bios/firmware for your motherboard? I would check that first.

Pleae read your manual page 11 at bottom.
It reads

Iggy, thanks, I did read that... "during system startup" is what's throwing me off... I was told Vista or 7 would take care of the Ram issue.... and I thought the Ram would be shown as 3.xx "during startup" only and fix itself up... the "total Ram" in the info center says I have 3.5Gigs installed with 3.5Gigs avail.
thanks for your answers and suggestions guys.

Actually you have an older motherboard and the 3.XX means that the xx could be any number. I believe your BIOS is using some of it.
Do you have Shadow RAM activated in your BIOS? or somehting that doesn't need to be used in Windows 7 setup?

Can't tell you any more. Sorry

I think you will find that the board itself is automatically reserving to map out a chunk of memory there due to the older design to start with. With Socket 939 and newer AMD boards since you have an old Socket A job the full 4gb becomes available. Most Socket As were geared to see 3 dimm slots for a 3gb maximum.

On newer boards the 32bit XP saw 3.12gb approximate while Vista was about 3.58gb the same for the 32bit 7. The 64bit Windows however will see the 4gb total with the newer chipsets. You're simply dealing with the hardware limitations for the old board there.

Thanks guys for the great responses.. i figured it was the age of the board that was the limitations but hey, it's not like I'm getting anyy less performance at this point, quite the contrary... this old dog is a hotrod once again. thanks again!
Cheers!

Isn't there a frame buffer setting in the bios since it is AGP? - there it goes...

hmmmm interesting. Don't know could that be what's eating it up... ?????