Ram hardware reserved

[Sean lac]

Hi I have a problem my PC has been running fine for years but all of the sudden my bios says total memory 8gb and shows 2x 8gb hyper fury x 1866mhz sticks of ram in the 2 dim slots Windows shows total ram 16gb but only 7.9 useable and 8.1gb is hardware reserved I have a Radeon rx 590 8gb dedicated gpu On my system I have tried resetting bios tested both sticks they both boot up on there own and cleared the cmos the PC used to recognise all the memory and 16gb was available but now it's not my board is a asus a68hm-plus ddr3 memory and amda10 7870k cpu please can you help me out before I end up buying a new mobo 

[Allan B]

There are a few suggestions online on how to fix this.  I assume you are running 64bit Operating system. 

The first suggestion is to update the BIOS on the motherboard to the latest release and also make sure the system will boot with only ram module installed in each slot.  Maybe one is bad?  

Another possibility is Windows is setup to only use 8GB...   This site has 4 possible solutions, I would look into 1, 4 and 2 in that order.

https://appuals.com/windows-10-wont-use-full-ram/