EULA

That's where the End User License Agreement (EULA) comes in. First, it states that "Before you use the software under a license, you must assign that license to one device (physical hardware system). That device is the licensed device." Microsoft has stated on their web site that the motherboard is the component that identifies a particular system. Their policy says "An upgrade of the motherboard is considered to result in a "new personal computer" to which Microsoft OEM operating system software cannot be transferred from another computer. If the motherboard is upgraded or replaced for reasons other than a defect, then a new computer has been created and the license of new operating system software is required."

This might lead you to believe that you are, indeed, out of luck. Ah, but wait - look at the language: for a reason other than a defect. Then read on in the EULA: "You may uninstall the software and install it on another device for your use. You may not do so to share this license between devices."

That means if you have to buy a new motherboard - or a whole new computer - because of a defect in the old one, you can install the software on the new device as long as you aren't still using it on the old one. Hallelujah!

Some folks, though, in trying to do what's legal, are paying more than they have to under the licensing agreements. For example, you buy Microsoft Office 2007 Professional and install it on your desktop computer. Then you get a new laptop and want to put Office on it, too. Do you have to buy another license? Most people guessed yes, but let's look at the EULA: "a. Licensed Device. You may install and use one copy of the software on the licensed device. b. Portable Device. You may install another copy on a portable device for use by the single primary user of the licensed device."

Ha! As long as you're the primary user of both systems, it's perfectly within the license agreement to install it on both of them.