No versions of Windows that has been released so far to date show complete file extensions by default. This can be dangerous as you may accidentally download a seemingly harmless image but it turned out to be a executable virus! For example, if a file is written as ‘trojan.doc.exe’ it would simply appear as ‘trojan.doc’. Most users usually get around this lack of file extension information by right clicking the file and viewing the properties. However… no one has time for that! Well you could make an eency weency little change in File Explorer (or Windows Explorer for prior Windows 8) and bam you have yourself the bonafide file extensions you desperately wanted!
How to show file extensions in Windows 8/8.1 and 10
There are two ways you can do this in Windows 8/8.1 and 10!
Via File Explorer directly
Navigate to the
Start menu and open
File Explorer.

Selec the
View tab.

Tick the checkbox
File Name Extensions. File extensions should now appear!
Via File Explorer Options
Navigate to the
Start menu and type in
File Explorer Options. Open it.

In the
File Explorer Options dialog box, navigate to the
View tab.

Under Advanced Settings, untick the box for ‘Hide extensions for known file types’.

Select
Apply.

Click
OK.
How to show file extensions in Vista and Windows 7
Navigate to Windows Explorer.

Selec the
Organize drop down menu and select
Folder and search options.

Navigate to the View tab in Folder Options.

Under Advanced Settings, untick the box next to ‘Hide extensions for known file types’.

Click
Apply to save changes.

Click
OK to exit.
How to show file extensions in Windows XP
Navigate to the Start Menu and select
My Computer.

In My Computer, select the
Tools menu on the menu bar in explorer. In the drop down, Click
Folder Options in the drop down menu.

Select the
View tab.

Look for a setting ‘Hide file extensions for known file types’ and uncheck the box to disable. Click
Apply to All Folders button.

The Folder Options should look as below. Click
OK.

Now you have configured Windows to always show you file extensions! The snippet below is taken from Windows 10 but you get the gist of how your files will appear in Windows Explorer/File Explorer from now on.