Microsoft on Tuesday was granted a patent for a way of limiting access to certain features of an operating system depending on whether a user has paid for those features.
The patent, titled "Restricted software and hardware usage on a computer," covers a means by which it can offer software that has features either enabled or not enabled depending on which edition a user has purchased. It's a concept already in use at the company.
Microsoft has already said it will offer, with a particular product key unlocking the features that come with that edition. Users will be able to upgrade to a higher-end version of Windows 7 just by purchasing a new product key, Microsoft has said.
It is not clear that the patented technology is used for this, although the two sound very similar to me. One piece of the application deals with the scenario in which "a consumer initially purchases a computer with restricted functionality at a price that is less than the price that would be charged for a computer with full functionality."
"Subsequently, the user can, at an additional cost, acquire a digital key that allows the restrictions to be removed, upgrading the computer to full functionality," Microsoft said.
Although Microsoft has long touted the general-purpose nature of Windows, it notes in its patent applications the need to offer different versions with different features.
"One problem inherent in open architecture systems is they are generally licensed with complete use rights and/or functionality that may be beyond the need or desire of the system purchaser," Microsoft said. "Consequentially, the purchase price of these systems being indifferent to usage scenarios means users with limited needs pay the same rate for these systems as those with universal needs."
With Windows, there have long been home and professional versions. During its long life span, Windows XP also added the Starter, Media Center, and Tablet PC editions.
With Vista, Microsoft added the Home Premium, Enterprise, and Ultimate versions. In that case, users could also move from one version to another, although it required the use of a separate disk.
The awarding of the patent was noted earlier on Wednesday on Slashdot.