How to view a computer file extension

Updated: 01/24/2018 by Computer Hope

To view the file extension of a single file for all versions of Windows, follow the steps below. If you want Windows to show the file extensions of every file on the computer by default, skip to the show file extensions.

Viewing the file extension of a single file

  1. Right-click the file.
  2. Select the Properties option.
  3. In the Properties window, similar to what is shown below, you should see the "Type of file:" entry, which is the file type and extension. As can be seen in the example below, this file is a TXT file with a .txt file extension. In this case, the file opens with the TextPad program.

Viewing file extension in Windows

Always show file extensions of all files

Users more familiar with computer files and file extensions may want to view all computer file extensions to help with locating and browsing files. To do this, follow the steps below for your version of Windows.

Windows 10

  1. Open the Control Panel.
  2. In the Control Panel, type file in the Search Control Panel text field. Click on File Explorer Options in the search results.
  3. In the File Explorer Options window, click the View tab.
  4. Uncheck the box for Hide extensions for known file type.

Windows 2000, XP, Vista, 7, and 8

  1. Open the Control Panel.
  2. Click Folder Options.
  3. Click View.
  4. Uncheck Hide extensions for known file type.

- OR -

  1. Open My Computer.
  2. Click Tools and click Folder Options or click View and then Options depending on your version of Windows.
  3. In the Folder Options window, click the View tab.
  4. Uncheck the box that says Hide file extensions for known file types.

MS-DOS and Windows command line

In MS-DOS, typing dir to list all files also displays the file extension of each file.

Windows 98 and ME

  1. Open My Computer.
  2. Click View.
  3. Click Folder Options.
  4. Uncheck the box that says Hide file extensions for known file types.

Windows 95

  1. Open My Computer.
  2. Click View.
  3. Click Options.
  4. Uncheck the box that says Hide MS-DOS file extensions for files that are registered and then click Apply and OK.