Problems within BootCamp settings

I started windows with my old 4GB memory and changed the boot configuration with msconfig.

I typed it in manually to the max memory 16384 MB and saved the settings. Then I turned it off and inserted the 16GB RAM again.

Then it started but when looking at the properties of my computer it says 16 GB installed but I can only use 2,16GB. So I opened msconfig again and changed the settings once more and restarted.

Now it says 16 GB installed. Strange... but as long as it works I'm happy :-)

Thanks and best Regards