Hi Guys it seems once again i'm having some issues with this DeskTop of mine.
One day it is working just fine and now it just wont boot up at all, maybe someone could advise a solution or at least tell me what this means.
As soon as i turn it on it comes up with this and that is as far as it will go.
It Says on a Black Screen.
Reboot and Select proper Boot device or insert Boot Media in selected Boot Device and press any key
Now i have no idea of what to do here, some assistance please and how i may at least advance past this point, how can i reboot the machine if it wont go past this point 
Thank you.
Leon 