windows 7 - RAM not usable?

I just upgraded my RAM today by adding 2 x 4GB 1333MHz DDR3 sticks on top of my 2 x 2GB 1333MHz DDR3 RAM, making a total of 12GB of RAM.

For some reason before the 4GB was all usable, but when I added these two it shows up that only 1.95GB of RAM is usable, and my actual computer rating by Microsoft dropped 2 points because of it O.o

Any idea what's wrong?

This is how it's set up in my system:

Slot 1 - 2GB DDR3 1333 (blue)
Slot 2 - 4GB DDR3 1333 (black)
Slot 3 - 2GB DDR3 1333 (blue)
Slot 4 - 4GB DDR3 1333 (black)

I did it this way because each component is color coded blue/black.

I bet this is some simple mistake, but it says that this RAM is compatible with my system and now only 2GB is working rather than the 4GB before, and the new RAM isn't working either.

Any ideas?