One of the most absurd defaults in Windows. In an attempt to make things simple, Windows is set from the start to hide all the file extensions when a file name is displayed in Explorer or any application dialog box dealing with file names.

File extensions were one of the more intelligent inventions in the DOS/Windows world, because the type of file is always attached to the file name. Even if novices have never touched a computer, they may have heard of JPEGs and GIFs. If users are ever to gain an understanding of the computer, one of the first things a new Windows user should do is make sure this important information is displayed. See Win Show file extensions and extension.