Turbo C (Structured Programming Language) in Full Screen Mode Error

When I opened my Turbo C (Structured Programming Language) software in windows 7 operating system for programming.
By default, Turbo C window opens as a smaller size.
Then I try to make it full screen by using the key combination Alt+Enter, but it gets failed to open in Full Screen.
This is my uploaded image,

This system does not support fullscreen mode.
OK
Please help me,
Thanks,
