How to Change File Extensions in Command Prompt

By Contributing Writer

Windows operating systems have the MS-DOS command prompt that allows you to manipulate—copy, delete and rename—files. In Linux, such commands are available via a terminal window. The way to change the file extension in both Windows and Linux is to rename a file providing the new extension.

Things You'll Need

  • PC with Windows XP/Vista or Linux

In Windows XP/Vista

Step 1

In Windows XP/Vista, click “Start.” Click “Run” (only Windows XP). Then type “cmd” and press “Enter” to open the command prompt window.

Step 2

In the MS-DOS shell window, type “cd c:\\path\\to\\file” and press “Enter.” Example:cd c:\\user\\test. If the designated file is on a different logical drive (e.g., on drive D) type “d:” and press “Enter.” Then type the “cd” command as above.

Step 3

Type “dir” followed by “Enter” to list the directory content and find the designated file.

Step 4

Type “rename filename.ext filename.new” and press ”Enter”; “.new” is the new file extension (\"filename.ext\" stands for any file you might have; for example: rename report.txt report.doc).

In Linux

Step 1

Right-click on Desktop and choose “open terminal” from the pop-up menu.

Step 2

Type “cd /path/to/the/file” followed by pressing “Enter” to navigate to the directory having the file. Example: cd /home/tom/doc.

Step 3

Type “ls *.ext” and press “Enter” to list all files with the extension “ext,” and confirm the file exists in this directory. For example: ls *.txt.

Step 4

Type “mv filename.ext filename.new” and press “Enter” to change the extension. For example, mv report.txt report.doc.

Tips & Warnings

  • A filename must not contain spaces to be renamed via the command prompt.