There are many how to build computers instructables and guides out there, but they all tell you to get certain parts.
You can use any parts in your computer as long as they fit. Once you have the right parts, you can build it in a short time. By "right " i mean the actual part, like ram, Hard drive etc
My computer didn't cost me anything to make, because i was able to get parts from family members, and scavenging.
Throughout the instructable, there will be links. I give a basic overview, and the links are for a more in depth look at the part.
I also give a relate each part to parts of the body if i can.
Also, keep In mind I have never taken any classes about computers, except for the typing class at my school, and that this Instructable is the most research I've ever done about computers, so try to keep harsh comments to a minimum please! It would help more if you tell me what I've missed without being sarcastic
Step 1: The Materials
To build a computer that functions, you only need-
-a Hard Drive
-a Processor with fan and heatsink
-256mb or more of ram
-a Power Supply Unit-(PSU)
-cables to connect it all
But to add form to function you need, in addition to that above-
-a case - AT, ATX, BTX, or LPX -a modem
-an ethernet card
and if you want it to be even better-
-a graphics card
-a sound card
-another hard drive
Step 2: The Motherboard
I have five motherboards, one is shot, one is in use and three are in storage. The motherboard is one of the most important part of the computer, kind of like a heart and Circulitory System. It circulates electricity like a heart circulates blood through the Circulitory System. The more important parts are the PCI, PCI-E, PCI-X, AGP, Processor, IDE ports, ram, heatsinks, fans, and the other ports that are found on the side, etc. etc. There are many graphics ports and PCI versions.
More Here http://en.wikipedia.org/wiki/Motherboard
Step 3: Processors
I have 2 processors, one Celeron, and one Pentium 3. they are interchangeable. The processor is like the brain of the computer. It processes commands like a brain does. There are different brands, and sometimes the manufacturer of the processors will make two different processor types and improve both. This is a little confusing. But research is always best if you're unsure.
More Here http://en.wikipedia.org/wiki/Central_processing_unit
Step 4: Hard Drives
Hard drives are like the memory of a computer. They store information on disks called platters.
Hard Drives typically come somewhere between 40 and 160. Laptop hard drives get up into the 320 range.
More Info here-http://en.wikipedia.org/wiki/Hard_Drive
Step 5: Graphics Cards
Chessman.exe says this body part would be the eyes. The Graphics card shown is an AGP, meaning it goes into an AGP slot, but they can go into any slot. The ports are typically a display port, S-video, and Digital Video Interface, or DVI
More info here http://en.wikipedia.org/wiki/Graphics_card
Step 6: RAM
RAM is like the short term memory of the computer. It stands for Random Access Memory. There are many other versions of RAM, like SDRAM which stands for Synchronous Dynamic RAM, Random-access memory is a form of computer data storage. It takes the form of integrated circuits that allow stored data to be accessed in any order for example, at random. The word random refers to the fact that any piece of data can be returned in a constant time, regardless of its physical location and whether or not it is related to the previous piece of data.
More Here http://en.wikipedia.org/wiki/RAM
Step 7: CD/DVD
CD and DVD drives are like the eyes of a computer. I don't have much to elaborate on this, except like the blu-ray did to the DVD and HD-DVD, they pretty much made floppys obsolete. They also come in any combination of CD, CD-RW, CD-ROM, DVD, DVD-RW, and DVD-ROM
There are a variety of things that you can do with a CD Drive DVD drive or better, from burning CD's, to Ripping DVD's and playing CD's and DVD's.
RW stands for Rewritable. In a CD drive, you can burn CD's, in a DVD drive you can burn DVD's
ROM stands for Read-Only Memory.
DVD-ROM and DVD-http://en.wikipedia.org/wiki/DVD_Drive
Step 8: Monitor/Visual Display Unit
This is the output of the computer.
Screen size is measured diagonally
More info here-http://en.wikipedia.org/wiki/Visual_display_unit
Step 9: Drive Connectors
Some drive Connectors are ATA,SCSI, and SATA.
ATA's, or are 20 pin ribbon cables used to connect the Hard and disk(ette) drives. They used to be 20 wires, but now are 40 still with 20 pins, and have been all but replaced by SATA
SCSI is a set of standards for physically connecting and transferring data between computers and peripheral devices. The SCSI standards define commands, protocols, and electrical and optical interfaces. SCSI is most commonly used for hard disks and tape drives, but it can connect a wide range of other devices, including scanners and CD drives. The SCSI standard defines command sets for specific peripheral device types; the presence of "unknown" as one of these types means that in theory it can be used as an interface to almost any device, but the standard is highly pragmatic and addressed toward commercial requirements.
SATA, or Serial ATA, is computer bus is a storage-interface for connecting host bus adapters to mass storage devices such as hard disk drives and optical drives. The SATA host adapter is integrated into almost all modern consumer laptop computers and desktop motherboards.
There are two types- single and double are what i call them, but really the first is regular and the second is master/slave, where the master is the main drive and the slave is the secondary.
ATA - http://en.wikipedia.org/wiki/AT_Attachment
SCSI - http://en.wikipedia.org/wiki/Scsi
SATA - http://en.wikipedia.org/wiki/SATA
Step 10: Modems
Modems, internal modems and wireless modems basically provide Internet and Ethernet to the computer.
More info here-http://en.wikipedia.org/wiki/Modem
Step 11: Operating System
Operating systems run the computer. Without an operating system, or OS, the computer has to run on a pre-installed OS, which is typically very basic.
Some OS's are
All the Rest-http://en.wikipedia.org/wiki/Operating_system#Examples_of_operating_systems
Step 12: Other Stuff
So i've covered Motherboards, Hard Drives, Ram , Monitors, Graphics Cards, Processors, Drives and more. But I haven't covered all the small but (fancy word alert) intrinsic parts of the computer
Computer Case-Contains Motherboard and other internals
Speakers-Gives the computer a voice
Heatsinks-cool down the processors
Step 13: Assembly
The assembly is pretty easy. See the pictures on the other pages for help locating the parts.
Motherboard - If you bought a motherboard, or took one out of a different computer, you have to make sure it fits into the case. If it doesn't, you'll either have to get a new one, or run it bare-bones. If it does,make sure the screw holes align, and screw it in
Processor/s - Stick them into the processor ports. Some of the corners are missing a few contacts, and if you put it in wrong, you'll squish the contacts on another corner, so check the bottom of the processor to be sure.
RAM - goes into the RAM slots. The different types of RAM have different contact configurations. By this I mean they'll have indentations at different points. For example, Some RAM have two indentations and some RAM have one, so make sure your motherboard is compatible before you buy it. If you scavenge it, it doesn't matter if you scavenge it because you aren't wasting any money
PCI cards and the like - goes into the PCI Slots and the corresponding slots to the like. First, you have to take off the slot opening dust cover. Just unscrew it. Then, push the card straight down into the slot, and screw it in using the screw from the dust cover.
Hard Drives - if you use IDE, find the IDE port on the motherboard and the hard drive. They look exactly the same on the hard drive as they do on the motherboard. Then, there is a four slot port on the back. This is where the PSU connector goes in. There is a notch on the side, so if it doesn't go in, turn it around and press it in until it sort of clicks, or snaps in.
Disk Drives - Connect it to the motherboard and PSU the same way you connected the hard drive.
PSU - If you scavenge this, it probably came attached to a case. If it didn't, then attach it, probably by screwing it on.
Connect all the cables, which should be easy, because most of the ports are different. If something doesn't work, unplug it, switch it and try again.
*If something doesn't work, look it up. It's pretty much common sense that if you are reading this and trying to build a computer, you already have a functional computer.*
**If you need to reference for any of these parts, look on the motherboard or intro page**
Step 14: A Quick Bit on Gaming and Enthusiast Computers
Gaming computers are built to be really fast so the end users can play games like WOW on.
Enthusiast computers are built to look cool. These type of computers usually include lots of lighting. Some lighting includes: LED's, Neon etc.
These computers usually run at a hotter temperature than normal computers, so the have a lot of heatsinks and cooling devices, including water cooling, and even liquid nitrogen!
Step 15: Thats It!
Thats all you need to know to build a functional computer. If you want to know more, use the links and Google.
I hope you viewers have learned as much about computers by reading this as I have adding in all the other reader's suggestions.
Please Enjoy This Picture Of Achmed The Dead Terrorist!
Step 16: Credits
The Commentors who know more than me about computers who've haven't rubbed it in my face, but instead shared their wealth of computer knowledge. Thank you!
and more that I've forgot