hard disk - need help

I have a 20GB Maxtor hard disk which after windows was unstable and I
done a fdisk that resulted the hard disk not recognise which did not
allow me to proceed further with completing fdisk on the drive.  I
have tried using Maxblast software from vendors but unable to revive
the hard disk.  At bios setup it was detected and recognised with no
problems, when booting up there was no hard disk installed being
displayed and can not fdisk nor format it.  Please enlighten me as to
how or know how either what happen to my hard disk. Just after the 3
yrs Warranty.