We asked Maximum PC's Will Smith to describe the cheapest PC you can build, and he said he'd do it, if only to talk you out of spending so little. Here's what you gain, and lose, by going ultra cheap.

Over at Maximum PC, we just posted a guide that show's you everything you need to know to build the cheapest PC I'd recommend to anyone for use as his or her main PC. It's a surprisingly beefy machine, capable of playing games, ripping DVDs, editing video and photos, and playing 1080p video with nary a dropped frame. For a mere $647, we managed to pack a quad-core CPU, a great video card, 4GB of memory, and Windows 7 Home Premium into a surprisingly fashionable mid-tower. However, if you don't need as well-rounded a general purpose PC, you can go cheaper, especially if you're willing to make some sacrifices. Let's take a look at the parts we used, and then we'll start making cuts.

Let's look at the price chart. If you're not a gamer and aren't using one of the handful of applications that's accelerated by general-purpose GPU-based computing, then there's no good reason to spend 25% of your budget on a videocard that will lie fallow for most everything you do. The Gigabyte motherboard sports integrated graphics that will do everything you need to do, including hardware accelerated decode for video playback. Pulling the videocard brings our total cost down below $500, to $481. Not too shabby, but we can save even more.

If you're not going to be running tons of apps, editing photos, or encoding videos, that quad-core is massive overkill. To save a few bucks, we're going to replace that quad-core Athlon II with a single-core Sempron LE-1250. It costs less than a Blu-ray disc at Best Buy, a mere $32. Unfortunately, that still doesn't get us below $400, so we need to dig deeper.

Since you ditched the quad core CPU, your PC won't be up to running many applications at once, so we can cut back on memory. You can buy a generic 1GB stick for $22 at Newegg, which is the minimum requirement for Windows 7.

Since you won't be creating content, there's absolutely no reason to spend big bucks on a massive 500GB hard drive. In fact, you could probably even get by installing Windows on a decent-sized flash drive, but that's more expensive than what we have in mind. It's tough to beat a more-than-adequate 80GB drive for a mere $35. Oh, and while we're at it, you should ditch the optical drive. Odds are, you won't need it for anything after you set up your machine, and it's easier and faster to install Windows from thumbdrive (which you probably already have anyway).

After more than halving the price of our PC, Windows is looking mighty expensive. At $105, the OEM edition of Windows Home Premium is more than a third of the total cost of this machine. It's time to start thinking about Ubuntu, which will get our total price down to a cool $200. But wait, we can go even cheaper.

If you're just going to browse the web on this machine, why spend money on a real CPU? A Foxconn Atom motherboard that comes with the CPU costs a few bucks less than our AMD motherboard alone, so it's time to trim the fat, yet again. Sure, we could spend a few bucks more and get the same CPU in a motherboard equipped with Nvidia's Ion chipset, but EVERYTHING MUST GO!

For a machine with power requirements this meager, there's absolutely no reason to spend 20% of our budget on a quality power supply. Instead, let's get a case that includes an integrated power supply. It may not be reliable, but it sure is cheap!

Now, I'm reasonably certain that there's no way to build a cheaper machine. The only bad news? You just built a nettop.

Don't forget to check out Will's complete guide to the cheapest PC he'd actually recommend you to build.

Will Smith is the Editor-in-Chief of Maximum PC and has been building PCs longer than he cares to admit. He enjoys long walks, Rock Band, and is anxiously awaiting the first great Android Phone and the Apple Tablet.

Top image by Tim Rogers/Flickr, used under CC License