Doing Fedora fresh install with Dual Boot

In the boot I have the choice between Windows and Linux. I think that primary is Windows and Linux occupies some Windows partition. But, I see that it also has some /boot sector. That is there is /sda1 is NTFS used for Windows, /sda2 is Fedora boot and /sda3 is Fedora main drive. Now, I want to update Fedora from 17 to 20/21. I fail to use yum because of keys and other problems. It cannot find fed-up also. They recommend fresh/clean install. As I understand, I need to use boot CD or flash. How do I do that? I cannot use usual Linux guide since they do not take NeoSmart into consideration. Where can I find the technical background which will explain me everything?