A technician is troubleshooting an "operating system not found" error message. Which of the following is likely the cause?

Memory failure typically results in stop errors (BSODs), unexpected reboots, or application crashes, rather than an "operating system not found" message at boot.

Power supply failure would prevent the system from powering on at all, or cause intermittent power issues, not specifically an "operating system not found" error.

An "operating system not found" error often points to an issue with the boot device, most commonly the hard disk drive (HDD) or solid-state drive (SSD), which stores the operating system files. If the HDD fails or is corrupted, the BIOS/UEFI cannot locate and load the OS.

Processor failure would typically prevent the system from booting entirely, often resulting in no display or specific POST error codes, rather than an OS not found message.