Let me elaborate on this very vital subject:
Jeepers, computer companies that sell desktops for "everyday" people, are doing nothing more than selling you bundles of junk. They cut costs, and pass the 'savings' onto you. How? They have many ways of doing so they can provide you with horrible speed ram, small amounts of it, a tiny power supply, a custom built mini motherboard (and by custom I mean it might as well have a hamster in a ball in the middle), an ancient cpu like a celeron that they tell you is "super fast" because its clock speed is (and that is not what makes a cpu powerful, it's the architecture mainly) instead of the latest technology cpu, onboard sound, onboard vga, the list goes on. Then they usually put it in their own specialized container, so tiny, that it can only fit a fan, like they would want you to have anymore airflow anyway. They are hoping it will die down and you buy a new one in a year or two anyway. They provide you with bios that cannot be overclocked, and their hardware life is down right depressing.
So in short, they only have one fan, and absolutely nothing of anything else because they are cutting costs, they want you to rebuy in a year, etc. Then they throw in the "super service call anytime tech support" to make you feel mushy inside about your purchase, so in a year you'll buy from them again. It's all about money..
**I also forgot to add: sometimes they have specialized parts that only can be bought from them and are manufactured only by them. In this way they return you to their business for upgrades.**