Help: 4gb installed RAM, 2gb useable

Check what it says in the BIOS. If that says 4 GB, check Control Panel -> Administrative Tools -> System Configuration -> Boot tab -> Advanced options -> up the top there is an option to limit the memory use -> check that "Maximum memory" is unchecked.

What happens if you have only one memory module installed?

Hey,

I'm actually having the same problem with my motherboard. I have 12gigs of RAM but my mobo and Win7 x64 are reporting 7.99/8GB. I know my problem is that my 1366 slot has some bent pins because my watercooling coolant leaked onto my motherboard and I took the cheap and actually better route of using an air cooler, so with that said I had put new thermal paste on my CPU and it got on the hinges of the mobo that keep it in the socket. I had taken a micro fiber cloth with supreme caution on my finger tip but low and behold a damn thread got snagged on a few pins. I'm hoping this is my problem because I thought my RAM had failed and immediately bought 12GBs of Mushkin Redline and still the problem persisted. Just wanted to state my story.

Other fixes I have found are reseat and exchange each module if you haven't already. Also make sure it isn't your motherboard. Check each stick of RAM individually and test every slot. I did this and finally came to the conclusion that for some reason my middle slot is faulty. My computer won't even post with it in there. I does however past POST with a stick in either the first or 3rd slot. So again do these things. I've read in other forums that this has helped just simply reseating them and resetting your BIOS. Hope this can help, as I don't want you to suffer what I have so far.

yes that might be the case please do check that and see if it is, if not we will try to snoop around to help you out