How to: Change a file extension using Rename.
Solution:
Change the 'View' options to make sure file extensions are visible, and then select the 'File' menu and select 'Rename'.
1) Open Windows Explorer.
2) In the left pane, double-click the folder containing the file you want to rename.
3) Select the 'View' menu and select 'Options...'. (The 'Options' dialog box appears.)
4) Click the 'View' tab.
5) Make sure the 'Hide MS-DOS file extensions for file types that are registered' check box is cleared.
'View' tabbed page
6) (Optional) To display all files and their extensions, make sure the 'Show all files' radio button is selected.
7) Click 'OK'.
8) Select the 'View' menu and select 'Refresh' to update the file display.
9) Select the file.
10) Select the 'File' menu and select 'Rename'.
11) Type the new name. (The existing name is replaced as you type.)
NOTE: To assign a file type, the new name must end in a period followed by the desired three-letter extension.
12) Press ENTER.
