Originally posted here by Unl3Ashed
I have an oponion may be I am right or not, but may be the HDD's sector 0 is a bad sector and contains bad cluster ( if cluster 0 of a hard disk is damaged, the HDD is useless ). I hope I am wrong.
Even if sector 0 was bad he should still be able to boot from a floppy.

Try f8 when booting. You have to time it just right. If you press it after the bootstrap loads then it's too late and the system will continue booting.You must have the boot order set to prevent a floppy boot.