One thing I can tell you - if you purchase a second Nook Color, and you use ADB to apply push installs to the NC, you may have to reinstall the USB driver when you plug the newer NC into the computer to get it to recognize.
So if this is your second NC that you are trying to connect to your computer for ADB push installs, be sure to visit here, scroll down and review the WinXP/Win7 USB driver installation:
http://nookdevs.com/NookColor_USB_ADB
You will not need to repeat step I and step II, but rather begin with step III.