When I turn on the computer last the last two days, it would have a blue screen that says something to the effect that Windows has detected a problem and is preparing to shut down to prevent damage to the system. I did a full system scan with Norton. It detected tracking cookies and heuristic virus. I went through the list the quarantined the virus. I even used the Norton Program Eraser and detected another problem and took care of it. I thought that the problem was solved. But, the next day, the same problem recurred. I went through the same steps and pretty much the same things were detected and taken care of as I've written above. In the middle of those two days, I tried to download Bluekill as you've suggested and was not able to do it. I was hoping that Bluekill would provide me with another way of taking care of the problem because Norton was unable to do it. I don't understand why Norton was not able to block the virus from coming to my computer.
Last night, when I turned on the computer, the first screen said "Starging Windows" but just just froze there. Nothing else happened. I turned on the computer and got a message that there was a problem starting Windows and the system was trying repair. It then told me that the system could not be repaired. I turned the computer off and on. I was given the option of restoring the computer to an earlier time. But, even when I tried, the computer was not able to restore it. Now, when I turned the computer on, I just get the black screen that says "Starting Windows" and it just freezes there. I cannot even start the computer in the safe mode.