What should I do if the memory capacity does not change after Win7 adds a memory stick?

Xiaobian went to buy a memory stick a few days ago. After plugging it into the computer, I found that the memory capacity has not changed. This is the shrimp situation. So Xiaobian actively explored and finally developed a solution.
The situation is as follows:
1, Xiaobian added a 2GB memory stick on the computer with 2GB memory, which is displayed on the third-party software.

2. Select the right-click property of the computer and enter the computer system interface to display 4GB of memory, but only 2GB is available.

The method is as follows:
1. After clicking the start button, enter ”system“ and search. Once you find the system configuration, click Open.