File extensions have been a part of Windows since the beginning. They’re convenient and at the time the best solution to the problem of how to open a particular file.

BearPup sometimes wants to open a file in one program, and other times open it in another. He asked the Answer Line forum for an easy way to do this.

Some of them may not even describe a file type. Before Windows started using them to associate files with an application, people used extensions for all sorts of things. But that was a long time ago.

Vista all updated, Works is the word processor and spreadsheet program, and neither Works program nor the file extensions for .xls or.xlsx show up in the File Association menu. The default program ...

Back in the pre-Mac OS X and macOS days, Apple’s System 9 and earlier relied on hidden metadata to associate files with apps. File extensions, those bits of text that follow a period at the end ...