My windows computer creates "recovery points" when installing software or hardware, or simply updating software. There is a list of these recovery points, organized by date. I think you should be able to choose a recovery point generated prior to the installation of your new Nook, and your computer will revert back to it's previous state. After that, you can try the installation again.

If there is a way to reset the Nook, I'd consider doing that as well.