A good tips from http://www.addictivetips.com/windows-tips/batch-change-rename-file-extensions-in-windows/. Please refer to the original article.
Batch Change/Rename File Extensions In Windows
Do you want to batch rename file extensions in one simple step? Changing each file extension separately can be a pain in some cases where you have to change extensions of more than 100 files.
One of method using command line. The method as follow:
- Select the folder which has all the files who’s extension you would like to change. As an example I have made a folder named “test”, inside this folder I have placed four images in .jpg format. To change the extension of the files inside the folder, press Shift and right-click on the folder and select Open Command Window Here.
- You will now see a Command Window with the current folderdirectory open. Now type the following command line,
ren *.(current extension name) *.(extension you want)
- Since I want to change the extension from .jpg to .jpg, in my case the command line would be,
ren *.jpg *.jpg
- Now all the files inside the folder will change to the extension you want. It’s that simple.