Well Windows seem to see all your ram. Your reserved for hardware is a bit high but I wouldn't worry about it because you have a lot of hard ware. Here is a little built in Windows 7 test you can do. This will tell you how Windows 7 judges your system.
Press the Windows 7 key
and the pause key
on your keyboard. Then in the lower left of that screen tick on Performance and Information Tools.
Then tick on Advanced Tools
. Tick on the top line.
Clear all Windows experience index and re rate this system.
Let it complete and post a picture of the results.
Here is the best way to post a picture on this Forum. Screenshots and Files - Upload and Post in Seven Forums
Don't mess with your ram setting at this time.