A、A Trojan may have infected the OS or worked its way into the MBR. What did you download recently that caused the problem?

B、I understand your concern, and will try to have your computer working again as quickly as possible so that you can finish your report.

C、If the paper was so important to you, you should have created a backup copy so you could finish it on another computer.

D、I do not understand why you are upset. I am sure your professor will understand and you will be able to turn in the paper tomorrow.