Locating source code for .NET 2003

I am writing a program that used .NET 2003 edition, but I cannot locate the source code to start the program or the screen with a selection of configuration program or cancel. I composed it in 2006 and the original group has stopped working with all the computers for more than 3 years and the support is showing that Compact Disc (CD) is blank. Another hard disk crashed few years ago. How can I locate the source code for it? Can anyone help me?
