An ATX computer case is a PC case that complies to the ATX (Advanced Technology Extended) computer tower specifications. This standard was introduced by Intel in 1995 and defines acceptable sizes for motherboards, desktop computer cases, and computer power supplies. Most computer cases fall into the ATX specification, which guarantees that other computer components will be compatible with the you purchase. You'll find that most (if not all) ATX cases are compatible with Micro ATX motherboards as well.
When you purchase your ATX computer case, you'll want to consider the size of the case. ATX full-tower cases can be very large, and very heavy. Most people will want to purchase an ATX mid tower case, which is a little bit smaller. More important than the size of the PC case's exterior however, is the size of your desktop tower case's interior. If you're planning on installing large graphics cards the ATX computer case will have to be wide enough to accommodate it, if you'd like to use a tall CPU heatsink/fan the mid-tower or full-tower computer case must be deep enough to support it.
If you are a dedicated PC builder, gamer or just looking to expand your system take a look at our large range of computer cases. You are certain to find a new chassis here whether you are building a new computer or are considering carrying out a case mod on an existing device.