The new Service Pack 1 version of Windows Vista allows end users to purchase the "upgrade edition" and install it on any PC — with no need to purchase the more expensive "full edition."
The same behavior was present when Vista was originally released, but the fact that the trick wasn't removed from SP1 suggests that Microsoft executives approved the back door as a way to make the price of Vista more appealing to sophisticated buyers.
Previous Windows version not needed for upgrade — Just after Vista was first released to consumers on Jan. 30, 2007, an article in the Windows Secrets Newsletter explained that the upgrade edition of the operating system could be installed on a "clean" hard drive. For whatever reason, Vista had been programmed to accept itself as a "qualifying product." This eliminated any need for users to purchase the full edition of Vista or to upgrade Vista only over an older instance of Windows.
The Feb. 1, 2007, article by Windows Secrets editorial director Brian Livingston explained that the procedure is supported by several built-in dialog boxes. This indicates that the trick had been deliberately included by Vista's developers.
To boost the sales of retail packages, Microsoft announced just over one month ago significant price cuts in Vista, beginning with Service Pack 1. The savings over the old prices vary among different Vista versions, such as Home Premium, Business, and Ultimate. In the U.S., the list price of the upgrade edition is at least $100 cheaper than the full edition. Smaller savings exist in other markets, such as Canada and the European Union, as shown in the table below.
The price reductions on the Service Pack 1 version of Vista are even more significant because the upgrade trick still works in SP1, rendering unnecessary the purchase of Vista's full edition.
Shortly after the hidden upgrade method was published, Microsoft officials publicly stated that the procedure would violate Vista's end-user license agreement. Section 13 of the Vista EULA (PDF version) says, "To use upgrade software, you must first be licensed for the software that is eligible for the upgrade."
"We believe only a very small percentage of people will take the time to implement this workaround, and we encourage all customers to follow our official guidelines for upgrading to Windows Vista, which can be found at WindowsVista.com, instead," said a Microsoft press representative quoted in a News.com article on Feb. 14, 2007. "Following these guidelines will allow customers to easily and validly upgrade to Windows Vista," he continued.
Windows Vista, Upgrade, SP1, Vista SP1