Answer in one sentences:

(1) What is a virus?
Ans. Computer virus is a small program, which infects the computer by corrupting the files, and uses the computers memory with out our knowledge.
(2) What is the use of UPS?
Ans. In the case of power failure, an UPS can supply power for some more time allowing you to safely shutdown the computer.
(3)  Name some of the antivirus programs?
Ans. Norton, AVG, IBM and Quick Heal.
(4)  How does virus affect the computer?

Ans. Virus enters the computer while surfing the net or through e-mails, as well as through infected floppies, CD’s and pen drives.