Every file has a name. Almost every file has a name that looks more or less like this: Some Name or Another.ext.
The part to the left of the period — Some Name or Another, in this example — generally tells you something about the file, although it can be quite nonsensical or utterly inscrutable, depending on who named the file. The part to the right of the period — ext, in this case — is a filename extension, the subject of this particular diatribe.
Filename extensions have been around since the first PC emerged from the primordial ooze. They were a part of the PC’s legacy before anybody ever talked about legacy. Somebody, somewhere decided that Windows wouldn’t show filename extensions anymore. (My guess is that Bill Gates himself made the decision, about 20 years ago, but it’s only a guess.) Filename extensions were considered dangerous: too complicated for the typical user, a bit of technical arcana that novices shouldn’t have to sweat.
No filename extensions? That’s garbage. Pure, unadulterated garbage.
The fact is that nearly all files have names such as Letter to Mom.docx, Financial Projections.xlsx, or ILOVEYOU.vbs. But Windows 10, with rare exception, shows you only the first part of the filename. It cuts off the filename extension. So you see Letter to Mom, without the .docx (which brands the file as a Word document), Financial Projections, without the .xlsx (a dead giveaway for an Excel spreadsheet), and ILOVEYOU, without the .vbs (which is the filename extension for Visual Basic programs).
It's annoying when Windows 10 hides filename extensions, for four big reasons:
- If you can see the filename extension, you can usually figure out which kind of file you have at hand and which program will open it. People who use Word 2003, for example, may be perplexed to see a .docx filename extension — which is generated by Word 2010 and can’t be opened by bone-stock Word 2003.
Legend has it that former Microsoft CEO (and current largest individual stockholder) Steve Ballmer once infected former CEO (and current philanthropist extraordinaire) Bill Gates’s Windows PC using a bad email attachment, ILOVEYOU.VBS. If Ballmer had seen the .VBS on the end of the filename, no doubt he would’ve guessed it was a program — and might’ve been disinclined to double-click it.
- It’s almost impossible to get Windows to change filename extensions if you can’t see them. Try it.
- Many email programs and spam fighters forbid you from sending or receiving specific kinds of files, based solely on their filename extensions. That’s one of the reasons why your friends might not be able to email certain files to you. Just try emailing an .exe file, no matter what’s inside.
- You bump into filename extensions anyway. No matter how hard Microsoft wants to hide filename extensions, they show up everywhere — from the Readme.txt files mentioned repeatedly in the official Microsoft documentation to discussions of .jpg file sizes on Microsoft web pages and a gazillion places in between.
- In the taskbar, click the File Explorer icon.
File Explorer appears.
The most frequently used folders and recently accessed files, shown by File Explorer. - Click or tap View.
You see File Explorer’s View ribbon.
Make Windows show you filename extensions. - Select the File Name Extensions box.
While you’re here, you may want to change another setting. If you can avoid the temptation to delete or rename files you don’t understand, select the Hidden Items box. That way, Windows 10 will show you all files on your computer, including ones that have been marked as hidden, typically by Microsoft. Sometimes, you need to see all your files, even if Windows wants to hide them from you.
- Your changes take place immediately.
Look at your unveiled filename extensions.