File name extensions are how OS X recognizes file types, and changing the extension is one way to associate a file with a different program. Sometimes, however, changing the file extension does not ...

Microsoft uses file associations to set default programs for opening different file types on all its operating systems. As a result, when you open a file, be it text, image, or document, on your ...

When you double-click a file on your computer, Windows may launch an application to run or display the file. Windows knows how to do this because it maintains a list of known file types and the names ...

When you open files that have a particular file extension, Windows will look at its configuration to determine what the default program should be in order to work with these files. The default program ...

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 since the ...

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 of a ...

One of our readers reported that all the file extensions have changed to some unknown file format. If so, it could be a virus! If a virus has changed all the files extensions to unknown applications, ...

Windows File Explorer provides a ton of options to change how you view your files. What you might not know is that a critical option is disabled by default, despite being vital to your system's safety ...

You might encounter a situation where you may not be able to open any .exe files or shortcut link files, i.e., EXE or LNK files. You might instead get a “Open with” dialog box, or it may open the file ...

1How to view file name extensions for all files on a Mac 2How to view file name extensions for a individual file on a Mac The default setting for Mac OS is to not display a file's extension. For those ...