I am running XP 64 BIT PRO, I have 4 x 1GB Sticks of RAM but system information says only 3.25GB?

The 4 RAM sticks are identical, all Corsair 800Mhz 5-5-5-12.
I was running 32 bit windows and someone said I would need 64 bit to run up to 8GB RAM, but it still says 3.25GB. Plus a minute ago it said you are low on virtual memory, which I have never seen before.

I recently did a full format and scan. The hardware is all top of the line and AMD 64FX-62 Windsor CPU. M2N32-SLI Deluxe MOBO.

My Video Card is Geforce 7950GX2 which has 1GB of memory for itself anyway.

Virtual memory is already set at 3558mb isn't that plenty?

A friend advised the Ram may be unseated or blown and to take them out one at a time to try and find the offending stick. Can anyone advise other contingencies please?

Have a look in the BIOS and see if you can run memtest86 from there, a lot of the more recent motherboards offer this facility. This is an excellent program that will display what memory you have installed and will also check it for errors - ideally it should be run for several hours error free (overnight is ideal).

If this doesn't report the full amount of memory then try reseating it and run memtest again.

It would also be worth confirming that the full 4gb is recognised by the BIOS when the computer boots up.

Hope that helps,

Now that WAS fast Orbrey.. will try memtest later. Thanks for that. Gonna check boot up after virus scan is complete.

ThanQ

Do you have a PCI Device installed? like a TV Tuner, or Sound card, or anything similar???

I have 3GB in mine, and I can only see/use 2.75GB (256mb missing) this is because of whats known as 'PCI Reservation' when I have my TV tuner installed its like this, if i remove the TV tuner, i can see/use the full 3GB

on boot (POST) the bios reports 3GB Installed, 2.75 available..

Im not 100% sure why it does that, but thats what causes it any ways, I asked asus about it and that was the response I got (PCI Reservation)

Well it has been suggested that my vid card is stealing the RAM, though I reckon the Igig and the double virtual is sufficient.

your video card would only steal it if its an on board card, it wouldnt steal it other than that...

you can specify an 'apperture' size in the bios, which is basically how much ram to allow your GFX card to use for texture cache IF REQUIRED, but this doesnt remove the ram from your total ram sum.

What mobo are you using?
** thanks OP **

Have you checked any issues with the BIOS version you are currently running?
Orbreys suggestion to check the reported memory installed in the BIOS, What can you see?
If you have a Vista disk you could boot and try memtest from there? What does it report?

x64 XP should work and support 4Gb (8Gb) try posting on the Corsair forums seems a faster way to an answer this board looks like it has been re:issued this year is your the new or old revision?

Corsair forums (http://www.houseofhelp.com/forums/forumdisplay.php?f=130)

the OP stated they are on an Asus M2N32-SLI Deluxe..
im on an Asus A8N-SLI SE (Socket 939)

You could try a Linux 'Live' CD and check the memory usage there.