In the Mac OS it is possible to change the default program the operating system will use to open a file when you double-click on it. After you have changed this file association, though, you may want ...

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 on a file in Windows 8, Windows will automatically open that file using a program that has been associated with that file's extension. There may come a time, though, that you ...

I should have put this in my book I just learned two Windows command line utilities that I never knew existed: assoc and ftype. Both will display or modify the file association list, and are ...

In Windows 11 or Windows 10, you can Configure, Export, Import File Associations and even set or change file associations and extensions using GUI, but there is no option provided to delete an ...

Jeff Werner is a software engineer and has been writing this column since 2007. Question: When I download any .pdf file it tries to open in word. I know I have some setting wrong. How do I change it?

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 ...

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, ...

In macOS, the Open With contextual menu that appears when you right-click (or Ctrl-click) on a file provides links to all the applications installed on your Mac that are associated with that file type ...

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. Windows uses a file’s extension–the part of the ...