Post a snip of your Resource Monitor - Memory tab.
Start button > type Resource Monitor in the box, hit enter.
Any new hardware lately?
New graphics card or RAM?
If you haven't refreshed your WEI, try that, strange at it seems it has helped for some people.
Hey guys Im also having a similar problem. I have just installed 2 4gb sticks or RAM. Bios reads it as 8gb. But In System Properties It says I have 8Gb installed but only 2.5Gb is uasable. I tried the Ms config thing as well.
Thanks.
That is a huge Hardware Reserved amount.
I have 8GB RAM with 9MB Hardware Reserved, something is trying to use your RAM.
Did you re-boot after clearing the Max memory in msconfig?
If not, then re-boot and see if it has made a difference.
When you add new hardware you need to refresh your WEI, your snip shows it's asking for the refresh. As mentioned above this has helped some solve this issue in some cases.
Both of you can:
Check your BIOS for any Memory re-mapping function, if you have it enable it.
Open Task Manager, Processes Tab, click the Memory header and it will list by most memory used. This should show you what is using your memory.
Post back the details.
Check your motherboard website BIOS update log for memory fixes.