Windows 7: Only half of RAM usable

I bought a Vostro 430 around two and a half years ago, and about a week ago, I got this weird message in My Computer Properties - Installed memory (RAM): 6.oo GB (3.96 GB usable). Does that mean that out of my 3 RAM Sticks, only 2 of them are working? And if so/if not, will this affect my computer performance (gaming, watching videos etc.)



Thanks

Hello Mintos45 and welcome to Seven Forums.

Could you post a screenshot of your resource monitor (memory tab)? It might give a better idea of how your memory is being utilized. How much usable RAM did you have prior to the issue first surfacing a week ago? Did you change out any hardware like a graphics card? Did you rearrange your RAM modules?

Resource Monitor

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You are probably running a 32 bit Windows version. Only the 64 bit version can address more than ~3.5 GB RAM.

I am running a 64 bit Windows 7 Professional.

I had 6GB usable RAM before.
Haven't changed out the Graphics Card.
I remembered rearranging the RAM Sticks.

If you go ahead and download CPU-Z, open it up and see what it says for your installed memory. If it SEES and recognizes your 3rd stick, then that's a bit of a strange predicament you've got. If it doesn't though, just go ahead and try to re-seat your memory stick or try another slot. If it's a dead stick, the system would usually throw up an error at POST so I doubt it's that, which is good.

You can do the same thing in the BIOS, somewhere in the menu you'll see installed memory and you can see if the 3rd stick is being recognized by the system.

Couple of possibilities. If the RAM modules are from different manufacturers, rearranging them could have affected how they're "seen" by the BIOS. You could check for bad modules by installing just one stick. Usable RAM should be around 1-1.5GB depending on how much memory is set aside for graphics. Check each module individually. I'm not familiar with how many slots your Dell mobo has. Assuming 4, and you're using only 3, Dell may have a specific requirement to use slots 1, 2 & 3; or 1, 3 & 4; or 2, 3 & 4 etc for optimum RAM performance.

Another thought. Did you happen to change out or bump the CPU? A bent pin can also cause erratic RAM behavior.

If your BIOS was changed (sometimes by malware, sometimes by design) something called Memory Remapping could have changed. If Memory remapping options appear in the BIOS at all, make sure it is turned on.

You could also check msconfig. Click the Start orb, and type: msconfig. Open Boot tab > Advanced Options button. In that window, there is a setting for Maximum Memory. Make sure the checkbox is clear (not checked), then reboot your computer.

I'm running out of ideas.

Oh yeah and you can try and make your system run a full POST by turning off 'quick post' (or a variation of that in your specific BIOS), or just popping out the CMOS battery (the little watch battery in your motherboard) while the power's off for about a minute. When you swapped out your sticks the system might have just never even noticed that somehow.

I'm not sure where to find the specific requirements for RAM Slots in my motherboard.
I haven't done anything with my current CPU (Came with the computer).
Memory remapping isn't in my BIOS and Maximum Memory isn't checked in msconfig.
I'm really stumped on this one.

It didn't work.