How To Change Default Programs & File Associations in Windows 10, 8 & 7.
Method 1. Choose the Default Program for specific extension(s).
Method 2. Associate a specific extension to open with a default program.
Extra: How to restore the default 'Open With' dialog for unknown extension(s).
Method 1. Choose a Default Program for specific file types (extensions).
* b1. If you select the Choose defaults for this program option, then a new window will open that lists all the extensions (types of files) that the selected program can handle (open). Look at the list of extensions and select any other extensions (files types) you want to be opened by the selected program. After making your changes, click Save.
Method 2. Associate a specific file type (extension) to open with a default program.
The second method is to choose a default program by extension.
1. Go to Control Panel > Default programs and select Associate a file type or protocol with a program.
Extra: How to restore the default 'Open With' ('How do you want to open this file') dialog for an unknown type of file (extension).
If Windows don't have a program associated with a file type then it will ask the user to choose a program to open the unknown file. In this question, the user must specify a program to open that type of file and optionally he can select the 'Always use this program' option, to always open the same type of file(s) by using the same program of app in the future.
If after selecting the 'Always use this program' option the user decides to change the associated program for the same type of file(s) then it can right-click at the unknown file and from the right click menu to select the 'Open with' option in order to associate a different program.
But, if the user changes his decision and doesn't want any program to be associated with the selected type of file (extension) there is no way, using Windows GUI, to break the program association and to restore the default 'Open With' prompt with this type of type (extension).
To restore the default 'Open With' dialog for a (previously unknown) file type (extension), you have to use the Windows Registry Editor. To do that:
- HKEY_CLASSES_ROOT
- HKEY_CURRENT_USERSOFTWAREMicrosoftWindowsCurrentVersionExplorerFileExts
- HKEY_CURRENT_USERSOFTWAREMicrosoftWindowsRoamingOpenWithFileExts