The computer I had in the 1990's was DOS and when Windows 3.1 came out I putchased a full retail Windows 3.1. I then puchased the Windows 95 and 98 Upgrade Disks. When I bought a new compter it had Windows XP OEM. I then purchased the Windows 7 OEM for that same computer. My question is that since I have purchased a full Windows OS (Windows 3.1), am I in position to buy upgrade disks for life? If Windows 8 came out, could I legally purchase an Upgrade Disk even though I have a Windows OEM on my system now?