In my first instructable I'll show you how to make a OpenELEC media streamer. This media streamer enables you to stream video, music and images from all kinds of sources to your TV or monitor. The software running on the media streamer is OpenELEC. OpenELEC is a very efficient Linux based operating system that runs Kodi (formerly XBMC), a very powerful media player software. Because OpenELEC sole purpose is to run Kodi it is very fast. In this instructable I use an x86 based hardware (Intel or AMD) however there is an OpenELEC version for other hardware such as the Raspberry Pi or even Apple TV.

The reason I choose the x86 based hardware is that for this purpose the overall performance is in general better than ARM based system such as the Raspberry Pi. If your looking for the cheapest solution the Raspberry Pi is probably the cheapest solution.

Step 1: Stuff You Need

A, preferably, small PC case sometimes referred to as HTPC case. The case will probably be placed under your TV so you probably don't want one of these full tower cases. Alternatively you can use the case of an old CD player or amplifier. This is cheaper but it will complicate your build when installing the motherboard, power supply etc. I choose the LC-1410mi from LC Power because of it's price, size and the fact that a 200W power supply is included. EDIT: If you don't have an old PC, shop for a used PC possibly with a small form factor and with a proper processor such as the AMD Athlon™ X2. I found them on Ebay for around $30 without OS (but that's not needed anyway). If you don't like the case you can scavenge them for processor, motherboard, memory, power supply, storage, coolers etc.
A power supply if not already included in the PC case
A motherboard micro-ATX or even better mini-ITX preferably from an old PC. Both micro-ATX and mini-ATX refer to the dimensions of the motherboard. The mini-ITX motherboard is smaller than the micro-ATX and probably the only option if you buy a really small case. I used the MSI B75MA-E33 from an older PC.
A processor that is compatible with the motherboard (also preferably from an old PC). Both Intel and AMD different socket for their processors and even successive processors of the same brand can have different sockets. I already had a Celeron G1610 (Ivy Bridge generation) from an old PC. The Celeron is cheap and more than capable for an OpenELEC media streamer.
A cooler for the processor. I advise to use the stock cooler that came with the processor since it is quiet enough for this purpose and the cooling is adequate.
At least 1Gb or RAM. Make sure that the RAM is compatible with your motherboard. I installed 4Gb DDR3 1333MHz from an old PC.
A storage device: USB drive, harddisk or solid state drive (SSD) depending on your budget and your requirements. Of course with USB your media streamer will boot slower than with an SSD. I choose a 128GB SSD, admittedly a bit of overkill.
Connection the internet either through ethernet (very reliable) or over WiFi. For WiFi you can use an PCI card or a USB WiFi stick. I choose the latter.
A remote control. The cheapest solution is to use a smartphone or tablet and install the free Kore app for Android or the Official Kodi Remote for iOS.
Some tie-wraps.
For testing you need a monitor, keyboard and mouse.
A separate PC with either Windows, OSX or Linux to create a bootable USB drive.
A USB stick of at least 1Gb.

The total cost of the build was $100 but only because I used processor, motherboard, fan, memory and USB WiFi stick from an old PC. On the other hand I could have saved money on the SSD by using USB instead.

Step 2: Assemble the Hardware

In this step you assemble the hardware.

First assemble the motherboard. Place the processor in the socket. Refer to the manual of the motherboard and the processor since this is different for AMD and Intel. Although this is not very difficult be careful with this step since you can damage the pins. Place the stock cooler that came with the processor over the processor. There is no need to apply paste since there it is already applied on the cooler.
Disassemble the power supply and the brackets from the PC case. This will provide you all the space you need for the next step.
Insert the assembled motherboard into the case. Make sure that the insert to insert the cover plate of the motherboard first and press it firmly into the PC case. The motherboard must be placed on top of the mounting points in the PC case. Connect the cables of the case to the motherboard.
Place the power supply and connect the cables from the power supply to the motherboard. Since the lay-out of every motherboard is different I refer to the manual of the motherboard for this.
Insert the brackets into the PC case.
Now connect the SSD or hard disk to the motherboard and the power supply.
Now take some time to rearrange and group the cables with the tiewraps. Make sure that the cables do not touch the cooler
Insert the peripherals (like a USB WiFi stick) into media streamer making.

Step 3: Test Your Hardware

In this stage the forthcoming media streamer will be tested before OpenELEC is installed. I advise to leave the case open. First of all this gives you a visual inspection while the machine boots and if something is wrong you have easy access to the components.

Connect a monitor, keyboard and mouse to the media streamer.
Press the power button. The system performs a self test and if everything works fine the boot menu is displayed (see image). If something is wrong the system will either not boot or will display a boot error probably accompanied with several beeps. If the system refuses to boot you probably haven't connected the power supply properly (or forgot to switch on the power switch of the power supply). If a boot error is displayed I refer to the manual of the motherboard for further action. Possible the problem is related to the CPU or the memory. Either way, power off the system and make sure these components are properly inserted.
While the system boots press F11 (for MSI motherboards. For other brands it can be F8, F12 or ESC etc)
While in the BIOS menu make sure that the USB drive has the highest priority. You'll need that while booting from USB for the first time.
When the hardware test is successful you can continue to the next step and install OpenELEC.

Step 4: Install OpenELEC

Now it's time a create a bootable USB drive. You need a USB stick with at least 1Gb memory. You need a separate PC with either Windows, OSX or Linux for this step. In this example I'll assume you'll have a Windows PC.

Go to the OpenELEC website and download Diskimage of the stable 64-bit build. You'll end up with a file with a .img.gz extension.This is a zipped file.
The OpenELEC website provides an excellent wiki that explains how to create a USB stick with OpenELEC.
For Windows you need 7zip to unzip the downloaded .img file and Windows32DiskImager to write the .img file to the USB drive.
Eject the USB and insert it to the media streamer. Now start the media streamer with the USB drive. The system now the OpenELEC installer starts from the USB drive and you're welcomed with a menu.
Choose the first option from the OpenELEC installer: Quick install OpenELEC.tv and follow the instructions. OpenELEC is now written to the drive of your choice. I choose the SSD.
Remove the USB and reboot. A few seconds later the Kodi screen is displayed.
Configure OpenELEC e.g install some add-ons.
Finally run some videos.

Step 5: Test the Media Streamer

When OpenELEC works properly it is time to move your media streamer to your TV set.

Depending on your situation connect de media streamer directly to the TV (through HDMI) or connect it to some intermediate piece of equipment e.g. an amplifier.
Boot the OpenELEC media streamer and you should see the familiar Kodi screen.
Now use the remote (the Kore app for Android or the Official Kodi Remote for iOS). It should automatically connect to the media streamer. If not, check your WiFi connection.
Run a couple of trailers to see if the WiFi connection works properly. If Kodi starts buffering reposition your wifi antenna or the media streamer.
If nothing works you may want to consider connecting the media streamer with an ethernet cable instead of WiFi.