Note: The issue is not caused by Windows downloading every language pack available.
For both Windows 7 and 10, the installation will take ~10 hours. The upgrade to Windows 10 from Windows 7 Premium OEM will take ~30 hours. I have also purchased a Windows 10 Home USB for a clean install, and it takes ~10 hours to install. I guess that is why they call it Windows 10. XD
However, let's go pre-installation for Windows 10. Running a clean Windows 7 OEM with and without mobo drivers installed, it will take over 5 minutes to log in, and after that, the CPU will idle ~10%, and go full utilization if I open anything, even Task Manager or cmd. If I move the mouse, the utilization spikes. Thinking Windows 7 OEM was the issue, I purchased 10 Home, and it took nearly 2 hours to finally get to the EULA. Before the purple set up screen appears, there is nearly a 30 minute wait.
I am now not able to access my Windows 10 installation, due to the black screen. The issue, however, is not the black screen, rather the ridiculously long loading times and obscenely high CPU utilization.
What I've done:
Loaded optimal BIOS;
Reconfigured for AHCI (SSD);
Installed latest drivers (Win7);
Swapped SSD for a platter;
Confirm SSD is healthy and read/write speeds are factory (they're actually better);
Dedicated > 40 hours researching why this is happening (not joking);
Installed Windows 10 Home from both USB3 and USB2;
Upgraded to Windows 10 Home from Windows 7 OEM;
Lost count of how many times I've installed the two;
Had a birthday;
Removed all other drives leaving only the SSD;
What I have not done:
Hit my computer;
Not hit my desk;
Dedicated the full SSD to Windows;
"Hold on to your butts."
Here is where it gets interesting. I am currently running Arch Linux with Cinnamon on the same SSD without any issues at all. With Firefox open, CPU is idling at ~2%, never exceeding 10%, and there is absolutely no latency or jitters while running the desktop. Expected, yes? I have also had multiple distros on this SSD, including the insanely resource intensive Ubuntu (Just testing. Never again.)
The next thing I am going to do is update my BIOS. However, my BIOS version is dated only one-day prior to the latest stable version on Gigabyte's site, so I am not sure it is going to do anything. If that does not do anything, then I am going to wipe the whole SSD and make it a windows only install, with the idea Windows has some sort of personal vendetta against multiple partitions on the disk.
I am wanting to post this while I still have a proper desktop, because I think it would have taken ~10 hours to write that from my Kindle.
Motherboard: Gigabyte Z68X-UD3H-B3
CPU: Intel(R) Core(TM) i5-2500K CPU @ 3.30GHz
SSD: Sandisk SDSSDP-128G
RAM: Corsair 1333MHz 8GiB DDR(>2<5) x 4
Video card: GK106 [GeForce GTX 660]
hwinfo Clean installation situation for both 7 and 10. - Pastebin.com
Plenty of download rate from the ISP.
Thank you, and thank you. Happy new year.