Never heard about HDD Password. May be some boot manager asking for it.
If it is then try to repair MBR by booting with another bootable media
If it asks the password to access the HDD, then
this method should help u to access the HDD from another HDD with WinXP
What u need to do is, just goto BIOS and select this perticular HDD as "Not Installed"
Now boot with other HDD in WinXp which will autodetect the HDD and allow u to take the backup of data. Then try low level format to recover your HDD.
Best of luck