|Open the command (line) prompt window. Right-click the title bar. Choose Properties. (You can also do the same by right-clicking a Command Prompt shortcut.) Choose Layout in the properties dialog. Uncheck "Let system position window." Set the top and left coordinates to what you'd like. Set the window size to what you'd like. |
Also, while you are at it, change the screen buffer width to something pleasant (the wider the width, the longer the line it will contain without wrapping) and set the height to, oh, like 3000. This will allow you to scroll back 3000 lines and make the command prompt much more useful in many cases. I usually check Quick-Edit mode on the Options tab, too. This lets you copy and paste to and from the window easily.
You will be prompted to apply to current window or modify the shortcut. You can have different shortcuts configured differently.