[adullday]

One sneaky way to keep a backup of your activations is to create a virtual machine using VMware Server or Player, activate it there, and save the image to a DVD-R. But you'll probably have to get another copy of Windows or you'll run into problems with Microsoft's copy protection that might deactivate the whole darn OS.

I'm not being very helpful, am I?

Mac users should keep a backup of the "Digital Editions" folder which is buried in their Library folder in their home directories.