Peculiarly, by default command prompt in Windows 7 does not get really maximized unlike other program window; however, there is a way to enable true maximized window of command prompt in Windows 7.
Click Start, type “cmd” (without the quotation marks) in the start menu search menu field. Command prompt link with icon will appear on the top of the list. Hit Enter from keyboard to launch the program:

Command prompt will open; type the following command in command prompt:
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wmic
and press ENTER to get Windows Management Instrumentation Command-line utility running into an interactive mode.
Now, click the maximize button to get a real full screen window of Command Prompt.
You will not get this maximized window mode if you click the maximize button before executing WMIC.
Right click the maximized Command Prompt window title bar and select Properties. In the Properties dialog box, tick the Quick edit mode check-box followed by clicking OK button:

Next time when you will open command prompt by typing cmd in the start menu search field and hitting enter from keyboard, it will start in true maximized mode.
Note: 1. To disable the mode, simple do the reverse. Enter wmic mode and uncheck Quick edit mode.
2. To exit from wmic mode, type EXIT and hit enter twice in command prompt or click the close (X) button.
