Like you, I almost always disable that "feature". As a programmer I think it's important to know exactly what types of files you're dealing with, if indeed they actually have a file extension. Not sure about the history of this so-called feature, but I think it dates back to the days of Windows 95 when Uncle Bill (as I like to sarcastically refer to Microsoft) wanted to make all PCs easily accessible for the relative no-nothing user. It's not Microsoft's most annoying feature, but it's up there. Almost as irritating as the (thankfully) now defunct Microsoft Office Assistant, which in my view was a contradiction in terms on a global scale.