I will be getting a refurbished Lenovo desktop, Windows 7 Home Premium, 64 bit, as my 2.5 year old ASUS, after many crashes, finally bit the dust. The ASUS had a Vista OS that Best Buy upgraded to Windows 7 Professional and I have the upgrade disk. Would it be possible for me to use that disk to upgrade the new Lenovo to Windows 7 Professional from Home Premium? Also, if this is possible, would I make the backup disks AFTER installing the Windows 7 Pro or before while it is still Home Premium? Thank you