New to PC's freshly built gaming pc not working properly

So I have decided to build a gaming computer from scratch and have noticed that everything has been running horribly. I just bought a bunch of games including black flag, skyrim, darksiders, and a few other big games. EVERY one of these games starts up fine then once I get to actually playing the game, the cut scenes, gameplay and movement are slower than imaginable and lag uncontrollably. Not sure what to do being new and all but am under a lot of stress seeing as i have above the recommended specs for playing ALL these games.

Any idea?

Please help.

Thanks!

I didn't find the right solution from the Internet.

References www.cnet.com/forums/discussions/new-to-pcs-freshly-built-gaming-pc-not-working-properly/

Branding Motion Graphics video