> OPTION ONE <
Delete the old Windows installation, for example:
- Boot the computer using the Windows 7/8/8.1 installation media.
- On the first screen, press SHIFT+F10
to bring up command prompt.
- Run the following commands at the command prompt.
(this will give you a listing of the disks on your system)
select disk #
(select the disk you want to clean, for example select disk 0
(running the clean command will delete all partitions on the disk)
> OPTION TWO <
Uninstall product key (see screenshot below).
Open the command prompt as administrator and type (or copy and paste) the following command.