Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Again with the Power Supply

I just wanted to confirm that the power supply is necessary for many computers, especially laptops. If I wanted to use a power supply, I can get a bigger external HDD for the same price (so I did). Note that my 80gb iPod works great on my laptop - so its not impossible for a large-ish HDD to be powered from my USB ports.Almost EVERYONE should be concerned with this. Why? Well, if it works on your computer that is great. But if you ever need information off the drive when your computer crashes, you run the risk of not having one nearby that works (or that it works on your new computer). Second, if you want to transfer some files to a friend's computer, it may not work.WD should just ship every unit with the power supply, or solve the problem so that no one needs it.