Change File Extension Associations

In Windows XP, navigate to Control Panel > Folder Options. In Windows Vista and Windows 7, go to Control Panel > Default Programs > Set Default Programs > Set Program Associations. From there, you can assign a program to open with (or associate with) a specific program (in other words, map the file extensions to an application). Earlier versions of Windows used the command-line interface (CLI) assoc command or the technician directly edited the WIN.INI file.