Burning an ISO file into Pen Drive may require if you use netbook which doesn't have optical drive or you are in a case where Optical Driver(CD/DVD Drive) is not working or you don't have any Black CD or DVD to burn ISO file into.
For above discussed cases, the best solution is to burn ISO image in Pen Drive, Thumb Drive and use it in computer.
Here is step by step guide on How to burn ISO into Pen Drive ?
1. Download Unetbootin from their Official Website
2. Save file in desired location
3. Now RUN Unebootin, from the location where you saved it
4. Unebootin will launch, Now select option(radio button) of Diskimage
5. Click on '...' and browse and select the ISO file which you want to burn
6. Select your USB Drive's letter and Hit OK
That's it, now the ISO file will be burn into USB Pen Drive.