Warranties on hard drives can differ on manufacturers terms and conditions, and whether the drive is OEM or retail boxed. The drive in your case should have the same warranty term as the computer package agreement.
Five years seems a little excessive, and I have never heard of any manufacturer offering this, in most cases the maximum is three years with minimum being one year on new drives. Refurbish drives normally have 30 to 90 days, again depending on sellers terms and conditions, but this can go up to 1 year from some outlets.
If you want definate information then check your computer warranty agreement, or contact PCW,Medion or Seagate. Seagate would require the model serial number for a reference.