How to Change File Extension in Windows

In this tutorial you will learn how to change file extension in Windows.
Assuming that the file is named myfile.txt, we will rename it to myfile.doc:

Step 1: Initially, check that the files extension is displayed (example: fileName.extension). In case it is not, go to Windows Explorer, press Alt and click on Folder Options in the Tools menu.

set system to display file extension

Step 2: Remove the ”Hide extensions for known file types” checkmark from the View tab. Click OK. You will now see the extensions of the files.

configure system for viewing file extension

Step 3: Right-click on file. Select Rename from the menu.

select Rename on file

Step 4: Replace the .txt from myfile.txt. with .doc extension.

change extension

Result: you have successfully renamed your file.