Thanks a lot Sandra and Simon for your patience and your nice feeling.
{ "Answering Lobo: Yes, it does boot from floppy...but the problem also happens there sometimes. So I have to make many tries (sometimes) to make it work." }
Very sorry, I gave that answer before because my problem was repeated many times and in many cases. So it put in my memory that feeling which - I can't now confirm 100%. It might be wright. But I'm not sure. I don't like to make any confusion. Of course I'm talking here about "Booting from floppy".
So, I wanted to retry it a little before by using the two floppys of "Partition Magic 7.0". It did boot very nicely. I repeated that many times...There is no problem at all.
Something else:
It happened to me many times (I don't remember, since fixing two HD's Or two separated Windows XP) that, sometimes, while putting my PC under electric tension, it does stop completly on the oppening page on the step:
" Detecting IDE Drives... "
That happens if there is a floppy or not, if there is a CD or not.
So, I have to cut the electric tension and start the computer again to make it work.
Does that have any relation to the problem?
Thanks a lot.