Why does the memory not increase after the Win7 system plus the memory bar?

Do not know if you have encountered and I have the same problem, is to add a memory on the computer, but the memory does not increase, or display as the original size of the memory bar, for this problem, how to solve it? Below I will give you my way to solve this problem (my notebook is WIN7 64 bits, originally for 2G memory, Add a 2G)

1, I in 2GB memory of the computer added a 2GB memory, on the third-party software display

2, select the computer right-click Properties, enter the computer system interface, display 4GB of memory, but only 2GB available. Here's a look at my steps to solve this problem.

3. After clicking the Start button, enter "System" and search. When you find the system configuration, click Open.

4. Click "Boot" and select "Advanced Options" and open.

5. Change the maximum memory to 4096 or turn it off and make sure.

6. Click Shut down or restart to take effect.