I little while back, I wrote an article on using Dual Monitors. Here's a snippet:
"With newer computers having the ability to run multiple displays, here is a ‘Geek Tip’ for those of you thinking about using two monitors on one computer. There are various scenarios, I am going to describe just a few. I currently have two systems here with dual monitor setups."
Here's a video showing the two different computer scenarios I have that use dual monitors in Windows.