Disable Hide Extensions for Known File Types in Windows 7

By default, Windows Explorer hides the file extension at the end of most filenames: This is the .doc at the end of a Word document, the .xls at the end of an Excel spreadsheet, or the .exe at the end of an application program. Hiding the extension makes it more difficult for you to accidentally delete it when renaming the file, but we think it also makes it more difficult to tell what a given file is. It can also make it easier to fall for ruses, as when someone sends an email virus in a file named payroll.xls.exe. If Explorer hides the .exe part, you may fall for the trick and think the file is just an Excel spreadsheet.

To make Explorer show filenames in all their glory, follow these steps:

1. Click Start, Computer.

2. Click the Organize button at the top, left side of the window, and select Folder and Search Options.

3. Select the View tab. In the Advanced Settings list, find Hide Extensions for Known File Types and uncheck it.

4. This one is optional: If you’re curious about Windows’ internal files and folders, and plan on investigating them, also select Show Hidden Files and Folders. You can change this setting after you finish looking around.

5. Click OK.