When you double click an audio file on the computer in an Explorer window, which program opens and plays it? When you double click a JPEG photo, which program is used to display it or edit it? What about PDFs? Does the right program always open or would you prefer another one was used? You can easily choose.
Whenever a file is double clicked, Windows looks at the file type – the letters after the dot, such as .jpg – and loads whatever program is set as the default for it. So double clicking a .doc file will open Microsoft Word, providing you have it installed, and double clicking a .txt file will open it in Notepad.
How do you get another program to open a particular file type?
In Windows 8, hold down the Windows key and press X for the menu in the bottom left corner of the screen. Select Control Panel and select Small icons in the View by list in the top right corner.
Click Default Programs and then click Set your default programs.
There is a list of programs on the left hand side. Suppose we want to change the programs that open in Paint. Select it on the left and on the right is says that the program has 3 out of 14 defaults.
What this means is that Paint can open a total of 14 different file types, but Paint is used for only 3 of them. There are another 11 file types it could potentially open, but some other program is set as the default.
To see which files Paint is used to open and which it isn’t, click Choose defaults for this program.
Look down the Extensions column to see which items are ticked. These are the file types for which Paint is the default. You can see that these are .emf, .rle and .wmf on this computer. If you wanted Paint to open any of the other file types such as .bmp, which as you can see are currently set to use Windows Photo Viewer, you would tick the box and click the Save button at the bottom.
If you didn’t want to use Paint for .emf files for example, do not clear the tick here. That would simply leave .emf as Not selected, like the .ico file extension in the list. Select a different program, one that can handle .emf files, and tick the .emf box in its extensions list.
It is a bit tedious, but you can select each program in turn and see which files it is set to be used with. Then you can modify the list if necessary. Just tick the file type boxes to steal the file extension from another program and prevent it from being used.
Although Windows 8 has been used in this example, the same principle is used in Windows 7.