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 my diatribe.
If you’re looking at the Documents on your computer and you can’t see the period and three-letter suffixes of the filenames (such as .doc or .docx or .xls or xlsx and .jpg etc.,) that are visible in the below screen shot, don’t panic! You need to tell Windows to show them.
In my opinion, every single Windows 7 user should force Windows to show full filenames, including the (usually three-letter) extension at the end of the name.
Warning! Filename extensions were considered dangerous: too complicated for the typical user, a bit of technical arcana that novices shouldn’t have to sweat. If you want to play around on Filename Extensions, possible risks were there that you could even damage the Operating System Files
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 any more.
I really hate it when Windows 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 2007 and can’t be opened by Word 2003 unless you use Microsoft Compatibility Pack.
✦ It’s almost impossible to get Windows to change filename extensions if you can’t see them. Try it.
✦ Microsoft Outlook forbids you from sending or receiving specific kinds of files, based solely on their filename extensions. You can find a list of 88 dangerous filename extensions, blocked by Outlook 2003, at office.microsoft.com/en-us/assistance/HA011402971033.aspx.
✦ 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.
If you want to know how you can make Windows to show Filename Extensions. Follow this link For the Step-by-Step Instructions To Make Windows Show Filename Extensions.