What are folder extension? How do I create my own extension?

Question

I have heard about file extension but never heard about folder extension.

I mean to say if I create a folder called test and then rename it to .test{ED7BA470-8E54-465E-825C-99712043E01C} it opens control panel instead of opening the folder.

So my question is how do I create my own extension? I tried searching a lot, but couldn't find anything valuable.

Thanks.

Answer 1

See that :)

http://msdn.microsoft.com/en-us/library/ms997573.aspx

If you can program, you can try that:
http://www.codeproject.com/KB/shell/namespcextguide1.aspx