So you're into gaming, and you're looking to turn that shabby computer into a gaming powerhouse? You do not need unnecessarily expensive gaming computer though, you just need some decent gaming hardware.
If you do not exactly know what gaming hardware is, I've put together a guide explaining what it takes to have a gaming computer. You do not needily need all of these components, so I've broken them down by level of importance.
3D Video Card
First and foremost, if you have to have a decent video card to play the latest 3D games. You can have the best computer around, but if it has a cheap video card, 3D games will appear to run as slow as if you had a slow computer. You do not necessarily need the latest video card, because at the rate they come out it will be outdated in a few months anyway .. unless of course you have $ 500 burning a hole in your pocket and you really want to.
CPU
Since your CPU is the heart of the computer, this one is kind of obvious. Like most things, you do not need the fastest CPU around, but if you want a real gaming computer, you'll want something at or around 3 gigahertz (or 3000+ for you AMD enthusiasts).
You'll also want something that has a fast front side bus. It's usually best to find a motherboard and cpu that have similar front side bus speeds, because they work together, and the overall speed of the front side bus will only be as fast as the one with the slowest speed on it. It's kind of like driving a sports car on a highway with a 55 mile per hour speed limit, the car might be able to go 155, but the highway will only let you go 55.
Memory
Also known as Ram, it's what applications and games use to store information, the more the better. It's good to have at least 512 Megabytes, but real gamers have 750 megabytes, to 1 Gigabyte or more. Memory is extremely cheap these days, it's one of the cheapest and simplest upgrades you can do.
It's not only the amount that matters though, they also come in different times. DDR2 is the fastest, cheapest memory you can get right now. If you have SDRam, you'll probably want to upgrade your motherboard and CPU so you can have faster memory. It's kind of drastic, but your games will most likely be sluggish if your equipment is that old. Regular DDR is good enough for gaming, it just does not have the throughput that DDR2 does.
Motherboards
Today's fastest motherboards have faster Front Side Bus. The Front Side Bus (or FSB) is essentially the highway that runs from the CPU to the Ram, the bigger the highway, the more traffic it can handle at once, making calculations faster. Another thing to watch out for is what kinds of hard drives it supports. If you want SATA or SCSI drives, either your motherboard needs to support them, or you need to purchase an expansion card to plug them into. You'll also want a motherboard that supports the fastest computer memory you can get, which is currently DDR2.
Hard Drives
Hard drive speed may not sound important, but it can be one of many bottle necks that your computer runs into if it's not up to par with the rest of your computer. If you purchase regular IDE hard drives, you'll want at least 7200 rpm (rpm = rotations per minute, the more rotations the faster the drive).
If you want real speed though, you'll want a Serial ATA hard drive (SATA), which is one of the fastest hard drives you can get without buying server grade hard drives (SCSI), which are pretty expensive. Your motherboard has to support SATA or SCSI though if you plan to purchase these kinds of hard drives, or you have to have a PCI expansion card to plug them into.
Sound Card
If you want gaming quality sound, then you definitely need to replace that stock or built in sound card for a decent gaming sound card. And if you want the full effect, go for a dolby 5.1 surround sound enabled sound card for that super crisp sound your games can produce. Mix that with some 5.1 enabled speakers, and your gaming experience just took a new turn.
Computer Cases
Ok, so computer cases are not that important for speed, but if you want your new gaming computer to look slick too, then you need a nice colored case. Your friends will be jealous, and you will finally be able to look at your computer and smile, because it looks so awesome.