Batch rename file extensions

Simple but can be very useful.

1. Open up a command prompt
2. Go the file folder containing the files you need to rename
3. Enter this: ren *.(current extension name) *.(extension you want)
4. If done correctly it will rename all the file extensions to the specified one!

Example:

ren *.jpg *.png <<< this will rename all jpg extensions found, to png extensions.