Reinstall OEM-installed Windows 8.1

One of the first steps of the re-installation process of Windows 8.1 is that it asks for a Windows key. There is a "bug" that prevents a valid Windows key from working when the general Windows 8 installation disk is used on a laptop with a pre-installed OEM version.

Fortunately, if there are no installation disks supplied, then Windows 8.1 can still be easily re-installed on such a laptop, for example on another partition or disk:

1. Get a copy of the Windows 8.1 ISO, e.g. "Windows_8.1_EN-US_x64.ISO" and extract the contents to a USB stick

2. Bypass the Windows key screen by creating an ei.cfg text file in the sources folder on the USB stick. It should contain the following (replace "Core" with "Professional", if you have a valid key for that edition):

[EditionID]

Core

[Channel]

Retail

[VL]

0

3. Restart the laptop with the USB stick in it. The initial Windows key screen is skipped. During the latter part of the installation another Windows key screen pops up. Here the genuine valid key can be entered

Notes

• It has to be a USB stick, an external disk will not work: Win 8 can only be installed from an USB stick or a DVD
• Unfortunately, I cannot supply a link to the above mentioned ISO file
• Make sure the BIOS settings are such that the USB stick can be booted from and is the first in the sequence of bootable devices. Check how to enter the BIOS and set the bootable USB device on the site of the laptop manufacturer. Each manufacturer has a different method. For Lenovo IdeaPad: press and hold the small round button next to the power adapter entrance during a reboot