How can I associate a data file to open with Notepad? My program creates files with an extension *.AAA and of course Windows allows me to use it with my program since it is just text data but I would like Windows to show the Notepad icon with my *.AAA files like it does with *.txt files. Can this be done with code in a VB.NET 2002 program? A good commented working example would be great. Simple answer would be to use *.txt instead of *.AAA but the name of the file is dependant on parts of my program recognizing what file to use.