How to Change File Extensions

File extensions are guideposts for your operating system.  Each extension is related to a particular program that is meant to read, write or otherwise use a particular file.  Without an extension, your system does not know what to do with a given file and cannot open it for use.  This extension lets you know what program the file is associated with, what program will edit said file and how to go about opening the file.  If a file has no extension, unless you figure out what type of file it is, you may not be able to access it at all on your computer.

In order to change a file extension, you must first know what you need the file to be and if it is properly associated with such an extension. If you change the extension to the wrong one, you may not be able to open the file at all or you can even go so far as to corrupt the original data as a program tries to read the file and display it for you. This can cause much more harm than good, so avoiding opening a file with the wrong extension is key to the safety of your files. Once you know what extension you need a file to be and that is it the correct one, you can physically change the file extension.

Changing a file extension is relatively easy. First, you want to make sure you can see the physical file extension. Normally, this is hidden from view so that you do not accidentally disassociate a file with another extension and program. You want to open up any folder and go to Tools, then Folder Options. Once this menu is open, you want to go to the View tab. Go down the options listed until you find a box checked that says: "Hide extensions for known types." Uncheck that box, click Apply and then close the context menu.

You will now be able to see the extensions for most files on your system.  You can change the extensions at this point to whatever you want for your given file.  You only want to change what is after the period of the file name.  You have a file named ABC.DOC, you would change the .DOC portion only to whatever extension you may need, such as .PPT, .RTF or .TXT.  When your extension is set, the image associated with it may change, too.  From there, you can then open the file up with the program you need to open it and have successfully changed the file extension.