You are working as a technician at Certkiller .com. You are asked to install security updates as
well as upgrade some device drivers on one of Certkiller .com domain controllers. Prior to
performing this service on the domain controller, which of the following should you do FIRST?

A.
Backup data.

B.
Remove peripherals.

C.
Format the hard drive.

D.
Disconnect the external monitor.

Explanation:
You should always backup data before performing maintenance in order to be able to restore
former working conditions as fast as possible if something goes wrong.