HI Crazypants
I am having the same issue with my MSI Mobo Z87 G45
First my iso install works I checked it on another laptop.
I have tried installing from usb key making it bootable using windows utility, and also tried to launch install from uefi setting in the BIOS ( used rufus to makes the uefi key)
the mobo either does not recognize the key or when it does I get please select a bootable device and press a key.
I also have tried with a USB external HD , and changed the boot priority to usb hd
and also with data, again set the boot preferences accordingly.
External and sata hd are always detected but I get in both situations insert proper boot device.
There only the optical drive solution I have yet to try , but Im 99 percent sure I would get the same error message, as the installation devices work on my other laptop.
Their is something I need to figure out and it comes from the motherboard .
Crazypants how did you solve this issue?
Help would be soooooo appreciated,
cheers