A menos que você desative a experiência de desktop Aero e altere o driver WDDM (Modelo de driver de vídeo do Windows Vista) para o driver de exibição compatível com o Windows XP, não há uma maneira fácil de ativar um prompt de comando real sem janelas no Windows 7
Fonte: aqui
Existe um truque mencionado mais abaixo na página que explica como abrir o CMD maximizado a cada vez.
1) Create a shortcut to cmd.exe and double click to open it.
2) Type
wmic and press ENTER to get Windows Management Instrumentation
Command-line utility running into an interactive mode.
3) Click the maximize button to get a real full screen window of
Command Prompt. With Windows 7 default installation setting, you can
also click the Command Prompt window title bar and drag it up to the
edge of Desktop to get the same maximized window.
4) 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. This step makes
Windows 7 “remember” to maximize Command Prompt to this particular
full screen window mode, each time you double click the cmd.exe
shortcut created in step 1!
5) Close the Command Prompt window (by click the X button or execute
exit command twice to exit from WMIC as well as cmd.exe).
Now, double click the same cmd.exe shortcut again, you should see
Windows 7 open Command Prompt in the same maximized, full screen
window mode again :-)