Re: No existing operating system
I've had better luck creating bootable Ubuntu USB sticks using the Universal USB Installer from PendriveLinux.com.
Also, if your PC can boot from that, you can use that to try out Ubuntu. Only thing not present would be a hard drive -- and that's connected through the controller in your PC.
Booting from LiveCD (or LiveUSB) is really the only way to see how well a particular PC will work with any Linux distro.
Ubuntu 15.04 Mate, Mint 17.1; MS Win 8.1, Win10 TP.
Will not respond to PM requests for support -- use the forums.