[SOLVED] Motherboard can't recognise hard disks

[Kalampakos]

I have an issue with my motherboard not finding bootable devices when I power it up. I just built the pc with a new case meshify s2, new motherboard z390 aorus ultra, new cpu i7 9700k, and new memory sticks 2* 3200 aorus rgb memory. The pc boots I enter the motherboard bios, it can see my cpu, ram, fans and my ssd hard drive, but it keeps saying "no bootable device".

I kept the ssd from my previous build, where it worked fine and I have windows 10 installed on it.

Any ideas? Thanks in advance.

 

[Calvin7]

Your holdover OS obviously isn't compatible with your new hardware. You need to reinstall it.