After pasting the code save your file with .bat extension
Then Open it.
What it does?
It just create a folder named autorun.inf in all of your computer drives ,USB,Flash Drives etc... and you can not delete this folder because inside this folder there exist a folder name con and windows does not all to create this folder and we just create it with some trick.
To Delete autorun.inf folder just replace mkdir with rmdir in the above code.