If you're not familiar with the phrase, Bill Gates famously used it a lot when he would demo software. It means that Microsoft had an internal policy of using their own software.
I was recently working on a programming problem in WPF so I googled one of my own articles about it and copied the example code into a project to run it. Surprise! It didn't run! It didn't do anything.
I know that I tested the software before I posted it. That's one of my internal policies. So what went wrong? My current theory is that I tested a slightly more complex version and then "cleaned it up" to make it easier to read by deleting unnecessary code. Except that, the code I deleted was necessary after all. Figuring out why turned out to be fun! WPF is so much fun! Almost as much fun as giving yourself an operation by looking in the mirror.
In any case, Part 5: A First Introduction to WPF and XAML for Visual Basic Programmers is expanded and retested now. You might want to start at the beginning. The link is on the first page of the link above.