If you don't care what hardware of software is included with your computer, buying "off-the-shelf" can elimate sorting through options you may not understand. In this case, all you need to know is what you want to do with the system and sales personel can usually recommend a system to fit those needs. With a pre-configured system, there is no waiting for delivery. Just go to the store and buy it. Even some dealers that build custom systems often offer popular packages to choose from. However, because there is a need to ship the system to you, you'll need to wait several days for delivery.

Some users desire certain hardware or software components in their system. Likewise, certain businesses require specific software or hardware for their equipment. In this case, going custom is the only way to pick and choose options.

Gamers are usually very specific about the hardware that goes in their computers. As a result, they often use vendors that customize every detail. This usually goes beyond even the options offered by Dell or Gateway. Companies like Shuttle or Alienware will allow customers to pick and choose just about every component of the system. However, unless you need that level of customization, you can usually get a system cheaper by opting for fewer choices.