I feel as if I should start from the beginning. I sold an unopened new Windows 7 HP product, which I purchased from Microsoft. I changed my mind shortly after the purchase and bought Windows 7 Ultimate, which I now have installed and love. The buyer returned it to me after opening it and attempting to install it using both the 32 and 64 bit disks. Fortunately I was able to retain the purchase price. I wish to sell it as a used product, but only if it can be installed and be activated by the new buyer. Is there a procedure for which the activation key can be checked to see if it is still valid, without installing it? The first buyer may have installed and activated it, causing the disks to be useless without a usable key. Thank you.