A "metering agent" would keep track of the charges, and a security module would create a verifying digital signature.

'Scalable Level Components'

Microsoft already uses subscription agreements for a variety of enterprise products, but this approach adapts the concept to individual users as well as companies. It covers charges per minute rather than an annual fee, and prices set by variables such as an option within an application or a level of performance.

Ironically for a company that has been accused of stuffing its products with unused features, the patent application notes that today's users might purchase a computer and applications with capabilities and performance that are only used on occasion.

As Microsoft's products have reached saturation levels in some areas, such as the widespread use of Office and the lessening need to upgrade, the patent application points toward new business models. Instead of a one-shot sale, the rental model offers what it describes as a "more granular approach." Users would not need to make purchase decisions based on total expected use, but on the "need of the moment."

To make occasional use more appealing, Application #20080319910 describes a computer that has "scalable level components" as well as scalable software and service options. Software and services could include word processing, e-mail, browsing and database access, among other things.

Rental of Computing Appliances

Microsoft's patent intention is not limited to desktop or laptop computers. For instance, it notes that renting could be useful for a "mapping and directions appliance" that someone might only need when venturing into unknown territory, but not for a normal day.

To accommodate management by an IT department or other supervisors, a user interface could allow a network administrator to establish the services that can be rented, the caps for charges for each service, and the rules for turning off metering during idle times.

The claims in the application make Microsoft's vision of pay-as-you-go computing sound like a digital version of a Chinese menu. There would be "a catalog of options," the ability to select an option, a calculation of the price of operation, configuration of the computer to accommodate the option, and final price tallying.

A running total could be shown in the user interface, and the user could have an existing balance in an account from which charges are deducted.

But to avoid having business users spend as much time making those choices as some diners take to order meal components, the application also offers the possibility of a preset package of settings and the ability to download the catalog for later use offline.