100% working!!!!!!!!How to burn arduino bootloader.

NOTE*****connect your Arduino as a PROGRAMMER with your Pc.
What is bootloader and how it works?
Bootloaders. A bootloaders is used as a separate program in the program memory that executes when a new application needs to be reloaded into the rest of program memory. ... The bootloader is used to reload application programs and contain the USB functions so the application programs can transfer data with the PC.