Why is half the memory being used?

Question

Iron

Win7x64 I
installed the second bar for 8GB, in the system properties I see 16 installed, 7.95 is used - what's the problem?
Planks are installed in slots of the same color

Answer 1

How did you determine that only half of the memory is being used?
This article is suggestive.
+ I agree with @oia : on the screen you can see 8243 megs reserved by iron, most often this is an integrated video card.

Answer 2

Which one is win7?
Home basic is limited by the marketing department to just 8GB.

Answer 3

Most likely the problem is in the boot boot parameters, msconfig will help.