This also a cool thing that notepad can do after renaming the .txt extension to .bat file.

Things Needed:
Only notepad

Procedure:
For an example,I want to rename 50 files with .avi to .rar. (well to encrypt )

1. First of all, of course open your Notepad.
2. Type in ren *.avi *.rar (in blue).
3. Save as the file as .bat. File can be named anything as you like but the important part is the extension .bat.
4. You are done! Now just execute and run this file in the directory where all the .avi files are located.

[note: avi in this example is the current extension whilr .rar is the extension I want to change the extension to ]

Notepad is very cool.
take a look at some other tips by notepad that I have written about that can be done using notepad.
-Lock Folders using notepad.
-List of redirecting folders [ an addition to the above topic ]

[source]
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