Buying a laptop hard drive or external/portable hard drive for someone who doens't have a great deal of knowledge could be confusing.  I sincerely hope the information below will help you when deciding to buy a hard drive or portable hard drive, and will also save you some money and headaches.

ALWAYS CHECK IF THE HARD DRIVE COMES WITH THE ORIGINAL WARRANTY

Notebook 2.5" hard drives sold on eBay could either have the manufaturer's warranty, used, a new pull, sold as is, refurbished or white label.  If your goal is to invest money on quality products, and mostly importantly, not be disappointed with your purchase, I would recommend you buy a product which comes with full manufacturer's warranty.  What does this mean? Manufacturer's warranty starts from the date the hard drive was manufactured and NOT the day it was sold or used.  Most hard drives and most manufacturers, including Toshiba, Hitachi and Fujitsu offer a 3-year warranty on the product, again from the day it was manufactured and NOT the day it was purchased.  Seagate now offers a 5-year warranty on its 2.5" laptop hard drives.

WHICH BRAND SHOULD YOU CHOOSE?

Major brands are Fujitsu, Toshiba, Hitachi and Seagate.  I personally think that the 4 companies provide excellent products.  Based on my experience with the 2.5" hard drives, I think that Fujitsu's hard drives are the quietest (whisper quiet.)  But again, whichever brand you choose might not matter that very much. All of the 4 companies I mentioned are really extremely reputable. It is perhaps a personal brand choice.  Just make sure to pick a new product with the warranty.

DO YOU REALLY SAVE MONEY IF YOU DECIDE TO BUY A HARD DRIVE WITH NO WARRANTY?

Imagine buying a hard drive or portable hard drive without any warranty. Let's say the hard drive is really new and never used before.  Remember, as I mentioned above, the hard drive warranty starts from the day it was manufactured and not sold. Imagine if for some reason or other, the hard drive fails within a short period of time.  Now what?  The seller is really not responsible at all, assuming that he/she stated everything part of the eBay listing.  It is very understandable that the buyer might feel betrayed, but this is the reason why I am writing this guide.  Saving a couple of dollars on a refurbished, white label, used, or as is hard drive, is perhaps not saving money at all. If the hard drive fails, you will end up losing all your money (unless there is some kind of warranty, either through the manufacturer or the seller.)

MAKE SURE TO CHECK WHETHER YOU NEED A SATA OR PATA HARD DRIVE

SATA is the next generation of portable 2.5" hard drives.  SATA (Serial ATA) is the successor to the legacy Advanced Technology Attachment standard (ATA, also known as IDE). IDE is the older technology which was retroactively renamed Parallel ATA (PATA) to distinguish it from Serial ATA. Fujitsu has established itself as the leader in the 2.5" SATA hard disk drive space delivering the industry’s first 2.5" SATA hard disk drive in the world in January 2004. If you are replacing a hard drive, just make sure that you are getting the one you need.  Check if the hard drive is either PATA or SATA. 

THERE IS NO SUCH THING AS A SONY VAIO HARD DRIVE

Hard drives are not made by Sony.  Sony Vaio laptops are equipped with either a Hitachi, Fujitsu, or perhaps another major brand drive. Some asked me if they could buy a Sony Vaio hard drive, and my answer has always been the same, which is THERE IS NO SUCH THING AS A SONY VAIO HARD DRIVE.  Your laptop is a Sony Vaio, but the actual drive is NOT.