Ram is Seated yet not Registering

[angusbcondon]

Hi, I have a problem with my Ram. I have seated both sticks (2x8GB) in the correct slots yet when I go into task manager it says 5.2GB free of 8GB and it says only 1 slot is taken up. What would the problem be and how can I fix it?

 

[camieabz]

Swap them over. Is it the same slot that's not showing, or is it the same stick of RAM? If same slot, ensure dual channel enabled. If same stick, give it a wipe along the contacts (ideally with an alcohol swab, then a dry, lint-free cloth), and try again.