When a file extension is not associated with a program, however, you are prompted by a "How do you want to open this type of file" or "Windows can't open this file" dialog when you try to open it.

An mp4 is a video file type, but the .mp4 in the file name is the file extension. Usually, these things should match, but it's possible for that not to be the case.

To open a file in Windows OS, you simply have to double-click on it. When you double-click on a file, Windows will automatically select the program the file is compatible with and open the file.

In reality, though, when you double-click on it, it would instead open in Notepad because its true, but not visible, extension is actually .txt, which corresponds to a text file.

Red Eye Rose received a file with a strange extension. She doesn’t know into what program she should load it. Neither does Windows. I doubt that anyone knows all of the file extensions used ...

Similarly, if you are downloading an AVI file, you can use a part of the sound file by removing .crdownload extension. You can then open and use the file to play video in a VLC player as long as ...

How to open a file with a different program on your Mac When you double-click a file on your Mac, the operating system will automatically open the file using the program assigned to that type of ...