The GUI Builder is a GUI development environment that enables amazingly quick and easy creation of screen data and screen transition buttons appearing on the LCD monitor display in target MCU systems. GUI Builder components have been added to Microsoft's Visual Studio 2010 for screen design (GUI interface) creation. GUI Builder includes a conversion utility to convert the Visual Studio 2010 screen design configured on your PC to a C language program. Use this to convert the screen design for use on the MCU as well. The C language program created with GUI Builder for the actual product can also be run on your PC as is for evaluation and debugging. This allows GUI development even without the actual device, greatly reducing turnaround time for GUI adjustments and debugging. Screen transition information can also be output, providing an excellent way to enhance test quality as you view the trial coverage. The graphics engines (GUI library and graphics library) necessary to link the C language program created with GUI Builder and run it on the actual device are available for all types of Renesas MCUs.