Thx for the reply, Peter.
Although your answer is not wrong as such, it is not an answer to my question. For a correct start up of the computer the boot sector of the hard drive containing the Windows installation, needs to be accessed ofcourse.
But every hard drive has a boot sector of its own, and it contains basic info about the hard drive (the number and size of partitions, for example). And during the bios phase of the start up, one can see that the bios performs a basic check on all hard drives to see if they are oke. It can do that only through the boot sector of that particular hard drive. But you are right when you say that the boot sector of the hard drive containing the Windows installation is the essential one.
I know some about this, beacuse I had a boot sector infection some years ago (which made me say goodbye to the free antivirus program and switch to my current NAV). My system then had two hard drives and both boot sectors were infected. So, it seems only logical that a scan by anti-virus software should be able to scan more than the boot sector of one hard drive. Now I only want a confirmation of that assumption.
But we are getting away from my original question, which you already answered in your first reply.
For my boot sector question I will search the forums, and if I cannot find an answer, I will make a seperate thread for it.
Thx again.