For the purposes of keeping troubleshooting simple, when you build your computer use the minimum amount of components needed to get to your desktop, install Windows, get online, update Windows, and download the drivers you need.
For example, you need the power supply, motherboard, CPU, CPU fan/heatsink, ONE stick of memory, ONE drive(OS drive), keyboard/mouse, optical drive(if using disc install), and wifi card if not using wired or if not built-in. You need the videocard only if you do not have integrated graphics with this build.
When you start adding components, do it one at a time and test the computer after adding each one. This way you'll know what's causing the problem, if there is a problem.