Answer:
Boot Sector Virus
Explanation:
A malicious software or malware is an executable line of code, programmed by a cybercriminal for ill intentions. There are many types of malware namely; viruses, rootkit, keylogger, trojan horse etc.
A boot sector virus is a kind of malware that runs before the operating system, affecting the boot sector of the hard disk, so even when a linux live cd is running as the operating system, the virus is still active.
Computer checkup/maintenance. You forgot to mention windows updates, it is critical to perform that action as well cause of the recent ransomeware malware that is going around lately and Microsoft and other OS vendors yes even Apple have released patches to prevent it spreading even further.
Application of a new technology and is much superior to rival products
How efficient well if we are transmitting 6bits and we need 10 to transmit the 6 bits that would be 6/10 = .6 = 60% efficient.