immediately type DIR and see if any files show up in the list. Don't type in a drive letter after DIR...just type DIR and press Enter.
I am suspecting that when you formatted the drive, you forgot the drive letter of C: and actually formatted the floppy disk and erased it.
If you change to the C: drive (or it does it automatically for you), type DIR W/P and see if any files show up for that drive letter. If any do, you didn't format your boot drive like you thought.
If I'm right, you will need to make a new bootdisk in order to install Windows.
I did all the hardware tasks that you and someone else suggested (re: Booting impossible). All the cables and pins are intact. I exchanged the drive for my spare one. The result was exactly the same. Which brings me back to suspect that it must be a software problem. Moreover, I completely cleaned the D: partition where the 98SE was in residence, i.e. I formatted it. That is when the diskette drive started asking to "please insert a diskette" although there was a booting diskette in it. Also, despite the formatting (which should have erased all traces of the 98? - or not?), when I start the computer, it still asks me if I want to boot into the 98 or the XP. If I say 98, it tells me that several programs are missing, and then gives me the C:> sign. It cannot be followed through, though, because there is no DOS now. So what say you - BIOS problem? Where, and how to tackle it? I am getting quite lost. Amos.