In Windows Vista, Windows 7, Windows Server 2008, and Windows Server 2008 R2 you can do the following to view file name extensions:

A file name extension is a set of characters added to the end of a file name that determine which program should open it. Follow these steps to choose whether Windows displays these file extensions.

  1. Open Folder Options. To do so, click the Start button, click Control Panel, click Appearance and Personalization, and then click Folder Options.

  2. Click the View tab, and then, under Advanced settings, do one of the following:

    • To display file extensions, clear the Hide extensions for known file types check box, and then click OK.

    • To hide file extensions, select the Hide extensions for known file types check box, and then click OK.

In Windows 8 or Windows Server 2012, you can do the following to view file name extensions:

  1. Press the Windows Key and X simultaneously. Then click File Explorer.

  2. Click View and then select the File name extensions checkbox. You may also select the checkbox titled Hidden items, if you want to view hidden files and folders.