We can use many softwares to make our pendrive bootable. But we will use mainly two softwares :
Software 1: Rufus
Software 2:Win 32 disk imager
When you will open rufus it will look like this.In the device panel select your pendrive.
Using Win32 Disk Imager:
When you will install Win32 Disk Imager and run it as "Administrator" , it will look like this.