There are scores of ways to do this. If you are looking for a simple windows like calculator, you can try coding in Java, if you know the language. Visual Basic is real neat, and I love the interface and ease of use. You can also use Visual C++ to do C coding, but it's much harder, and requires a lot more knowledge of Windows programming. With all this, the best solution I have seen for you is Java, with it's wonderful GUI support. If all else fails, just try using C code (you can use Notepad or any pad you want, not the ladies version though :) !) You will need to download the C compiler to do this. Google for TC compiler for example. Here is an example (out of millions) to build a simple calculator in Java. http://dmdoc.object-tools.com/dmBuilder/tutorial/java/calculator/index.html