You can also try pressing ESC as soon as the graphic appears and you will
see the text that makes up the loading process. You may see a message, such
as kernel panic, etc.
You can try burning at a lower speed with the same ISO or you may have to
download a new ISO if it does not work.
It is not likely your PC.
You will eventually get a Window that says Install Kubuntu or Try Kubuntu.
If you know that you are installing then you can go ahead, but you may want
to make sure it works on your hardware before installing.