johnbl :
You only need a valid windows OS to get the special discounts when you purchase the windows 8 key. if you are doing a clean windows 8 install it will not check the previous OS.
True, but the OP purchased the 'Upgrade' Edition, which has to be installed on a system that has a valid, qualifying Windows OS that has been activated. i.e. XP SP3, Vista SP2 or Win 7. The 'Clean install' comes about because it is physically impossible to upgrade XP to 8, hence the disk format prior to actual installation. However, if you download the upgrade version of 8 from M'Soft, the Upgrade Assistant will already have established that you have a Valid Qualifying OS, and a Key is issued on the strength of that linked to the Key of the Qual. OS AND the serial number of the System's Mainboard. Then you can use the Media of your choice to install Win 8 anywhere you like on the System, either 32 or 64 bit, and on a brand new disk if desired. I suspect, but haven't put it to the test, if you upgrade from an Upgrade Disk as in this instance, once activated, it would be possible to re-install at a future date without having to re-install the Qual. OS. Mebbe... Hope this clarifies the situation!