Please refer to below webpage and Microsoft website for more information and restrictions. You can perform a clean installation of Windows 8.1 if you purchased Windows 8.1 on DVD or purchased a download of Windows 8.1.
To perform a clean installation using a DVD or USB flash drive A clean installation typically means formatting your hard drive before installing Windows, so make sure that you have backed up your files and created recovery disc by MSI BurnRecovery tool before proceeding. If you bought Windows 8.1 on DVD or created a DVD or USB flash drive when you purchased and downloaded Windows 8.1, follow these steps to perform a clean installation. Turn on your PC so that Windows starts normally, insert the Windows 8.1 DVD or USB flash drive, and then shut down your PC. If that does not work then there is an issue with the SSD or the computer and you would need MSI or a real computer shop (one that does its own in-shop service).
Your laptop will boot from Windows 8.1 DVD or USB flash drive.
A Clean Install would be activated with the Digital Entitlement. Press any key when prompted by message “Press any key to boot from CD or DVD…”.
