Getting error message as " A bootable device has not been detected"

Hello I am new to Proxmox... I tried the proxmox in Hyper-V and it's working fine but I cannot open the console due to kernel nesting issue, so I installed in the physical machine, but I got the error message after reboot the machine as " A bootable device has not been detected" Please refer to the product guide....

Please advice

Intel Core i3 Processor
DH61ww Motherboard
16 GB RAM
1 TB WD Enterprise HDD

Suresh