Fresh Windows 8.1 Install on OEM Laptop

When you have a Laptop with Windows 8.1 preinstalled, then you will find yourself having a hard time installing a clean copy of Windows 8 on said Laptop. That, however, might be desirable for various reasons and so I am telling you how it's done. In my case, I am doing it with the firm intention to encrypt the system partition with TrueCrypt Setup 7.1a, which requires me to have an MBR rather than a GPT. There are probably ways to change this in-place, but there's really no point because I want a clean install of Windows anyway.

Getting the ISO

First, you go to the TechNet downloads site, then select Windows 8.1. Look for the version you want, most likely that'd be Windows 8.1 with Update (multiple editions) (x64) - DVD (English). Click the little Details link below the item and look for the SHA-1 hash of the ISO you chose. The aforementioned one has the SHA-1 checksum 4652DC6EBFEBE02C6A63E167C36E3FAEDFB93999. Now, punch that hash into google in search for some way to download that ISO. It is legal to download the ISO if you have a license to install and use this version of Windows, which I am assuming you do. Next, you should make sure that the ISO actually is legit:

>>> from hashlib import sha1
>>> s,f = sha1(), open("en_windows_8.1_with_update_x64_dvd_4065090.iso","rb")
>>> while True:
...     b = f.read(4096)
...     if b: s.update(b)
...     else: break
...
>>> print(s.hexdigest().upper())
4652DC6EBFEBE02C6A63E167C36E3FAEDFB93999
>>>

Installing Windows

Next, put that ISO on a bootable USB drive and install Windows. If you cannot boot from your perfectly bootable USB stick, you have to enter your BIOS and disable all advanced options that even remotely sounds like: * Intel Smart Response Technology/SRT * Secure Boot * UEFI only (as opposed to Legacy devices)

Bonus Objective: Switching to MBR

During install, after the welcome screen, you can hit Shift + F10 to launch a command prompt. If you want to convert your partition table to MBR, start diskpart and perform a list disk. If your disk is number 0, enter the following commands to convert to MBR:

select disk 0
clean
convert mbr

Bonus Objective: You somehow need to enter a product key

On my machine, I never had to enter a product key. However if you do, refer to this superuser post.