If you are a standard user, the following post will not help you, but if you are a power user with multiple Windows Vista Keys sitting around from MSDN, TechNet, Betas, Roadshows, Retail...

You may run into the problem (when flattening and rebuilding a box) of not knowing WHICH key (from your drawer of installation media and keys) goes with which computer.  If you have not yet formatted the box (and the OS in question is Vista, simplly pull up a command prompt and type slmgr -dlv

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This will cause the Software Licensing Service to pull up up a nice view of your current license information, amongst which is a partial Product Key.  That should help you find the right key for the right computer, so you don't have to call up the licensing number and explain why your Vista installation is changing hardware.  Good times!

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