Retail warranty runs from 1-5 yrs.
OEM very short warranty or none. See below.
Aside from the contents of the drive package, the other big difference between OEM and retail hard drives for some manufacturers is the warranty provided on the drive. Most drive makers with big OEM contracts sell those drives at a lower price to the OEM because they are specifically excluding warranty coverage from them. Nothing comes free in this world, including warranty support. The OEMs save money by not buying warranties on the hard disks they use in their systems. The condition of the deal is that the OEM will provide warranty coverage for the drive. It's important to understand that this is commonly done not just for hard disk drives but also for many other components used in PCs: optical drives, memory, video cards and even CPUs. If OEMs did not do this, the people who buy PCs would be paying for all these individual warranties. Instead, the PC maker provides a warranty that covers the entire system, and the buyer of the system is supposed to go to the OEM for service.