Editing Setting up the Computer

You have built your computer and hopefully everything is working as it should but you don't have an operating system. Here is where this page of the wiki is helpful, this page will guide you through everything you need to do to get your computer ready for you use. 

Here is what to expect when first turning on your computer

Initial Power On:

Connect monitor to GPU (not motherboard unless using integrated graphics)
Connect keyboard and mouse
Plug in power cable and flip PSU switch to "ON"
Press the power button on case
What to Expect:

Fans should spin up
LEDs should light up
You should hear a single beep (if speaker connected)
BIOS/UEFI screen should appear
If Nothing Happens:

Check all power connections
Ensure PSU switch is on
Verify front panel connectors are correct
Try reseating RAM
BIOS/UEFI Setup:

Enter BIOS (usually DEL or F2 during boot)
Check if all components are detected
Enable XMP/DOCP for RAM to run at advertised speeds
Set boot priority to your installation media
Save and exit

Next you will need your operating system

Create installation media on another computer (Windows/Linux USB). These can be found online. Use the official one from Microsoft and be wary of what Linux distributions you install. Make sure the download you use is safe. 
Boot from USB drive
Follow installation prompts
Install motherboard/chipset drivers from manufacturer's website
Install GPU drivers from NVIDIA/AMD/Intel website
Run Windows Update or equivalent

Once all of those steps are complete you should have a working computer booted into what ever operating system you choose. We would advise that your run some stress tests to make sure eveyrhtign is working optimally and monitor temperatures to make sure nothing is getting too hot. Don't worry if it seems like something is too warm. It is most likely fine and within operating temperature. Modern hardware will shut itself down when it gets too hot to protect itself.