Install Linux using Bootable USB.

Create a Bootable USB Flash Drive:
Just download the UNetbootin software and save it somewhere useful, double-click to run.
I chose to use an already downloaded ISO image of the Ubuntu installation cd, and then chose my USB flash drive, and clicked the OK button.

Now,your USB become bootable.Don't forget to change your systems booting sequence i.e USB first.

Download UNetbootin