How to change several file extensions at once!

Say you have several files of same or different file extensions in windows OS and you want to change the extension of all those files to a single extension then here is a simple trick to do that using cmd.

For example I have several php and html files in my directory and I want to change all those files extension to .txt

First you need to open the cmd in your folder. To do that simply enter your folder and hold the shift key on the keyboard and right click on your mouse and select open command window here.

Then just type in
ren  *.*   *.txt

Then hit enter and you will notice that all the file extensions will change at once.
To change to other extensions just change *.txt to *.required_extension