Secure Boot is a security standard to make sure that your PC boots using only software that is trusted by the PC manufacturer. This is activated by default in some PCs which ships with Windows 2012, 8 or later.
Most of the computers have option to disable secure boot and it is found under PC’s firmware (BIOS) menus. It can be launched by pressing "F2" during the boot.
Most PCs recognize Fedora 20, so try booting with Fedora 20 instead of 17. But if you really want 17, before you disable Secure Boot, consider reading the page : http://technet.microsoft.com/en-in/library/dn481258.aspx
Have you Windows 8[.1] installed too? if not not, AFAIK Fedora should not require secure boot enabled. Are you sure you have downloaded it from "http://get.fedoraproject.org"?
How did you prepare your USB stick for installation?
I followed the instructions on http://docs.fedoraproject.org/en-US/Fedora/20/html/Installation_Guide/Making_USB_Media.html
So, from windows, i downloaded the liveusb-creator and browsed for the downloaded iso and installed to the the previously formatted usb stick.
That is a Fedora 20 guide. Don't you think it would be better for you to use a Fedora 20 image instead of Fedora 17?
"secure boot not enabled" is printed by the boot loader included with Fedora, not the firmware. In other words, Secure Boot is already disabled, and the computer has already started Fedora. The error has nothing to do with Secure Boot.