The file extension is required by the system in order to determine which program should process this file, with which program it was created and how it can be changed. Typically, the extension is three distinct characters after the period in the file name.
Instructions
Step 1
By default, Windows Explorer does not display file extensions. This is done in order to increase protection against rash changes to files. In order to be able to change extensions, you must enable their display. Open "my computer". In the "Service" menu, select "Folder Properties". On the View tab, in the Advanced Options menu, find the Hide Extensions for Registered File Types item. Uncheck this box.
Step 2
In order for the extensions to be displayed on all folders of the computer, in the "folder view" parameter, click the "apply to all folders" button. Now all computers folders are configured as the current one, with file extensions displayed.
Step 3
Find the file you want to change the extension of in Explorer. By right-clicking on it, select the "rename" item in the context menu. Now you can change the name and extension of the file. Remove the old extension (three characters after the period) and replace it with the new one.
