After OS is restarted, a message is displayed, indicating that the system boot option cannot be found.
Restart the processor board. Press DEL to enter the BIOS. Choose Boot > Boot Device Priority > 1st Boot Device, and set the local hard disk as the boot device.
The boot device sequence in the BIOS is changed. The external storage, which does not have an OS, is mistakenly set as the boot device. As a result, OS startup fails.