# 32-bit Win 7 shows 2.5 GB RAM installed but 2.0 GB usable



## PC Hobbyist (Nov 26, 2009)

I know that a 32-bit system cannot see more than a little over 3 GB of RAM although my motherboard takes max 4 GB. But I'm confused about something else (I think). I have Win 7 32-bit with 2x 1GB modules and 2x 256MB modules running in dual mode (accoriding to CPU-Z). 

However, Win 7 system information shows: "2.5 GB installed (2.0 GB usable)".

CPU-Z says 2.5 GB of memory
WCPUID says 2 GB of memory

I also have an nVidia GeForce 9400GT card with 1 GB of DDR2 RAM.

Why does Win 7 only show 2 GB of usable RAM? Is the video card affecting that? So, are 512 MB of RAM truly being ignored?


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## Matthew1990 (Nov 26, 2009)

Go to msconfig, boot, advanced, if maximum memory is ticked, untick it.


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## PC Hobbyist (Nov 26, 2009)

Matthew1990 said:


> Go to msconfig, boot, advanced, if maximum memory is ticked, untick it.


I just checked that and it was not ticked.
Any other thoughts?


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## mac550 (Nov 26, 2009)

have you had a look in the BIOS for any possible memory conflicts


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## G25r8cer (Nov 27, 2009)

The other 500mb is being used for something with graphics I believe


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## PC Hobbyist (Nov 27, 2009)

mac550 said:


> have you had a look in the BIOS for any possible memory conflicts


The BIOS only shows 2 GB of memory. Strange that Win7 says 2.5 GB installed, but then it agrees with the BIOS and says 2 GB usable.
I still don't know why that is.

All modules are DDR 400 (PC 3200).



G25r8cer said:


> The other 500mb is being used for something with graphics I believe



I thought the video card might have something to do with it, but I'm not sure. I would have thought that the BIOS would still report the 2.5 GB and maybe Windows would only show 2 GB.

Anyway, I really wish I new why this is happening. I'm a bit confused with the whole matter.


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## linkin (Nov 27, 2009)

Try removing one of the 256mb sticks and see what happens.


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## 88Jonsson (Nov 27, 2009)

G25r8cer said:


> The other 500mb is being used for something with graphics I believe



G25r8cer is correct, the rest of your memory is being used by your graphics card.


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## Cromewell (Nov 27, 2009)

It's not necessarily the graphics card, there's other stuff that draws on the high range of addresses. I don't think I've ever seen a board that uses 2GB for IO mapping but that doesn't mean it can't happen.


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