Set up without a product key

[admin]

The Windows Vista setup process makes it appear that you have to enter a product key to install the operating system, just as you do with Windows XP. But that's not so. Regardless of how you start the setup program, you'll quickly come to a dialog box that asks you to enter a product key. Leave it blank, and then click No in response to the "Are you sure?" dialog box. You'll be presented with a list of all the different Vista versions available on the DVD. You can pick one and use it for up to 14 days without any hassle. After 14 days, though, you'll need to enter a valid product key or do a fresh install.

A single Windows Vista DVD contains the code for every version. Normally, you unlock the version you plan to use by entering a product ID that is specific to that version. If you leave out the product ID, the Setup program has no way to know which version you own. So you get to choose your version. This is an ideal way to test different versions for up to 14 days, after which you have to either enter a product ID or do another clean install.