Unhide Your File Extensions

There are many things that Microsoft does that I do not understand.  Most of these are technical in nature, but one non-technical thing they do just defies logic for me, and that is to hide file extensions by default.  Before you mumble ‘What’d he say?’ and tune out, let me explain.

The term file extension is shorthand for file name extension. Every file in a Windows system has a name, e.g. 'Our Spending Summary' or 'Capital Humane' or 'BBQ in Bluejeans'. But for Windows to have some idea as to what sort of content is in the file and what program it should use to open the file, the filename has to have an extension.  So the rules are that the filename must end in a period followed by three alpha characters from a pre-defined  long list of standard extensions.  So those file names above may actually be 'Our Spending Summary.xls', 'Capital Humane.pdf', and 'BBQ in Bluejean.doc'. Windows will use a default program to handle each file type.  For example, it most often would open an XLS file with Microsoft Excel, a DOC file with Microsoft Word, and a PDF file with Adobe Acrobat Reader.  The defaults may vary from machine to machine depending on the software installed, but in any case, Windows has a default program associated with every file type on every machine.

On my computers, you can open up Windows File Explorer and see file names and their extensions.  But on most machines, you will not see the extensions unless someone has told the machine to show them.  That’s because Microsoft has decided that by default all Windows machines are delivered with file extensions hidden.  Why they do this, I do not know; it makes no sense to me.  Instead, they may give you a hint by putting the associated program’s icon in front of the file name in Windows Explorer (recently renamed File Explorer in newer versions of Windows).  That’s fine, but the icons are the size of dandruff flakes, and are even more incomprehensible to the average person than those ‘universal’ markings on elevator door controls.

If I have ever been called to work on your computer, rest assured that your machine now shows filename extensions by default, because I always make sure they are set that way. You may ask why this is important. For one thing, a better educated computer user is a more skilled user, but more importantly, hackers are using this hidden file extension setting to advance their exploits.

One common and very powerful file extension is ‘EXE’. This stands for ‘Executable’ and means that when double clicked, the file will carry out a set of instructions.  That’s good if the instructions are to open your tax program and prepare it for entry.  That’s bad if the instructions tell the system to lock all your files or generate a steady stream of pop-ups.  Hackers know that their best chance for delivering a nefarious payload is to do it surreptitiously. So they send you a file named ‘Cute Kitty.jpg’.  A JPG file is designed to contain a picture of some sort.  But what if you have file extensions hidden, and the real name of the file is ‘Cute Kitty.jpg.exe’? It is the extension after the last period that is the real file extension. So which file are you more likely to open?  ‘Cute Kitty.jpg’, right? If your file extensions are hidden, you don’t even know that ‘.exe’ is there and ready to bring down the hammer.

The good news is that if your file extensions are hidden, they are easy to unhide. The method will vary a bit depending on your version of Windows.  If you are still running XP, open My Computer, click on Tools, Folder Options, and click on the view tab.  Look down the column for ‘Hide extensions for  Known File Types’ and uncheck it.

If you are running Windows Vista or Windows 7, open ‘Computer’ and click on Organize, then Folder and Search Options.  In the next window, click on the View tab, look for the line that reads ‘Hide Extensions for Known File Types’ and uncheck it.

If you have made the move to Windows 8, your path is slightly different (gee, that’s a surprise.) Go to the Control Panel, click on Appearance and Personalization, Then on Folder Options.  Click on the View tab, and look for the line that reads ‘Hide Extensions for Known File Types’ and uncheck it.

It’s little wonder that people get frustrated with Microsoft.  We’ve just seen a perfect example of how they are constantly changing the way to do the simplest of tasks, seemingly creating change just for the sake of change. Ah, but that is a rant for another time.

There’s nothing immodest about un-hiding your file extensions. It’s a smart thing to do.