There are two parts to the answer.
The command shell option /k starts a new command prompt, runs some command (or a program, batch script, or group of commands) and the prompt remains rather than terminating.
In this case, the command is
mode, which can be used to set the command prompt screen size/window buffer so it’s 200 columns wide and 70 rows high.
Finally, if you want to change the default size of the command prompt, right click on the title bar, select ‘Properties’, and select the ‘Layout’ tab. You can set the size of the screen buffer and the window separately. The width should be the same for both. The screen buffer height setting determines how far back you can scroll.
/K | /C Are used to run a command after launching cmd.exe. Thus you are running the command/program
mode. With mode there are several options the 200,70 is to change the display, but there are a few other options that can be used with mode.
As to the reason you can’t maximize cmd.exe is the screen buffer. You should check out this site that will show you how to change it.
Windows runs cmd.exe like most other Windows applications, in a window. Clicking on the maximize button “maximizes the window, but it’s still a window.
Under earlier versions of Windows, the command prompt could be switched to full screen (as opposed to a window) by pressing ALT/Enter from within the command window. ALT/Enter again returns to windowed mode. I just tried it on my Vista desktop and got an error saying that my system doesn’t support full screen mode, however, that may be because I have multiple monitors. My Windows 7 laptop appears to ignore ALT/Enter.
As for the cmd.exe switches, open a command window and type “cmd /?” or “help cmd” and you’ll get lots of detail.