Microsoft announced to get Windows 8 Pro Upgrade offer with buying of Windows 7 PC. This of is available for Home users and students who will purchase a qualified personal computer which will be period of promotion with valid Windows 7 OEM Certificate of Authenticity and product key. This offer supports following Windows versions.
Windows 7 Home Basic, Windows 7 Home Premium, Windows 7 Professional and Windows 7 Ultimate.
for full details visit
Microsoft website