A user powers on a desktop computer and the following error appears on the monitor: os not found. The user notes there are no visual indications of an error. A reboot yields the same result.
Which of the following is the MOST likely cause of the issue?
A . The system partition is set to active.
B . A USB flash drive that contains offline diagnostics is plugged in.
C . The CD-ROM drive contains a Windows setup disk.
D . The boot order has changed.
Answer: D