Thank you everyone for your comments.
This happened two weeks ago. Since then I have been
reading up on the stuff so I can understand this a little
better before I do anything. At least I know now what an
MBR is and what an encrypting virus does--back then I didn't.
I don't remember exactly what Fdisk's message was, but in
essence it said that there was possibly a virus and did I
want to continue (with collapsing the partition). I didn't.
(I have now checked the bios: it has 'C000 Write Protect 64K'
enabled. Could this have caused the message?)
The scanner had named the virus and I wrote it down--but
misplaced the paper. (It was Letters and figures, I think.)
Another scanner had detected nothing.
The disk is unformatted now: I did a 'government wipe'
with Norton. And it was after the wipe that I tried to run
Fdisk (without options)--and got that message.
So once the disk is reformatted, I'll scan for the name of
the virus again--to make sure it isn't one that encrypts the
MBR, as you said. - Of course, I won't use the /MBR option
unless I have to--and try to take precautions if I do.
(Backing up PT (+MBR), as someone suggested, would be
impossible at this stage. But I'll remember it.)
I am grateful for your explanations. Different people had
told me different things (e.g., Fdisk /MBR), but none of
them had actually experienced a virus. And everyone agreed
that I shouldn't have done what I did. Well, this was my
>Fdisk doesn't recognize a virus, but it may recognize that something
>is 'amiss' in the MBR. It simply rebuildss the entire master boot
>record. What was the message, and if named, what was the virus?
>Fdisk /MBR is safe to run on an empty disk, IMHO, and I have used it
>numerous times to eradicate viruses. However, I only used it on
>viruses that I knew didn't encrypt the MBR (Form A, Natas, Anti-Exe).
>Some viruses encrypt the MBR (Monkey) and using Fdisk /MBR will make
>your hard disk unreadable.
>In your case I would use Fdisk /MBR from a clean boot disk. You can
>re-partition your disk without worrying about losing any data.