Processor performing worse than it should be.

I have a desktop that I use for gaming. The specs are at the bottom. I bought my computer originally, but since then I've upgraded it a lot. Other than the case, hard drive, and some wiring. As I said this is a gaming desktop so how come I can run GTA V at about 10-15 fps at lowest settings, while my friend who has a computer slightly better, still run the game at about 70 fps on highest settings? Not to mention I only average to 120 fps on CS:GO with no fps limit, while the same friend runs it at about 400 fps. His build is only slightly better. His having a six-core AMD processor. Also if I'm playing anything and try to load Google Chrome it takes ages. In my BIOS it says I have 4 cores but everywhere else says I have 1 core and 1 logical processor. My computer should be reading my processor as 8 cores, as it is a 4C/8T processor I understand that BIOS is the absolute final word, and everything saying that I only have 1 core doesn't bother me. It's just that my processor is performing a lot worse than it should be. Every time I open Skype my processor usage shoots to about 80%. My friend has the same amount of RAM except his is DDR3. I have updated even updated BIOS and still didn't work.

Processor: Intel® Core™ i7-6700K @ 4.00GHz 4.01GHz (Quad-Core)

Motherboard: Asus Z170-A Series

RAM: 16GB DDR4

GPU: NVIDIA GTX 970

CPU Cooler: DEEPCOOL Gamer Storm CAPTAIN 120 CPU Liquid Cooler AIO Water Cooling

Power Supply: 650W Thermaltake Power Supply

OS: 64-bit Windows 10

Task Manager Screenshot: https://gyazo.com/47aa6804990287a599ae8b56cbaa6f9d

Enviroment Variables: https://gyazo.com/50f28a0fe2781082ed4f362b0e5700d2

DxDiag Report: ------------------
System Information
------------------
Time of this report: 3/2/2016, 16:31:57
Machine name: NEVERTRUSTNANNE
Operating System: Windows 10 Home 64-bit (10.0, Build 10586) (10586.th2_release_inmarket.160222-1549)
Language: English (Regional Setting: English)
System Manufacturer: System manufacturer
System Model: System Product Name
BIOS: BIOS Date: 07/17/15 16:58:14 Ver: 05.0000B
Processor: Intel® Core™ i7-6700K CPU @ 4.00GHz, ~4.0GHz
Memory: 16384MB RAM
Available OS Memory: 16314MB RAM
Page File: 4090MB used, 28607MB available
Windows Dir: C:\WINDOWS
DirectX Version: 12
DX Setup Parameters: Not found
User DPI Setting: Using System DPI
System DPI Setting: 96 DPI (100 percent)
DWM DPI Scaling: Disabled
Miracast: Available, with HDCP
Microsoft Graphics Hybrid: Not Supported
DxDiag Version: 10.00.10586.0000 64bit Unicode

DxDiag Previously: Crashed in DirectShow (stage 1). Re-running DxDiag with "dontskip" command line parameter or choosing not to bypass information gathering when prompted might result in DxDiag successfully obtaining this information