I purchased Windows XP software from Amazon through its reseller, Andrew Morgan/RetailSoftware for $123.99. I am not knowledgeable about software and I purchased a product to upgrade Windows 2000, but accidentally ordered one for Windows Millennium. The error was mine; I didn't realize there was a difference between 2000 and Millennium. I did not open the software, only the instruction book. When I realized my error and contacted RetailSoftware/Andrew Morgan, I received no response at all until I left negative feedback at Amazon. At that point, RetailSoftware agreed to accept return of the software conditioned upon my purchasing replacement software from him for $393.99 (later lowered to $219--for an item available on ebay for $135). When I left negative feedback for Amazon, Amazon instructed me to return the software to RetailSoftware/Andrew Morgan for a refund, which I did. Now Mr. Morgan has my money and the software. Be very, very careful if you do business with Amazon. Their A-to-Z Guarantee is a joke. And be even more careful if you do business with RetailSoftware/Andrew Morgan.