Basically no boot device could be 1 of three things listed below.
1. You have connected an incorrect external device and the system responds to boot from this however no operating system is available. Hence the error. What to do : You have disconnect, reset and select the correct bootable device. 2. You have a faulty hardware specifically your bootable harddisk, corrupted or malfunctioning. You have to reformat and correct the bios installed on the disk. 3. You have not selected correct bootable device. - Select the correct harddisk, if you have partition, be sure to select the one with the Operating system is installed to.
