Member Rara Avis
Hehe. When you open the Reply form in a New Window, you get exactly that - a brand new window. If your window is full screen, you don't see the one you just left. But it's there.
At the bottom of your monitor is a grey bar called the Task Bar. On the left side is the fancy Windows logo and Start Menu, and on the right is probably your digital clock. In between those two, are buttons, each one representing an open window. Click on one of those buttons and you change to that window. If you want to be able to see all the windows at the same time, right-click somewhere on your Task Bar where isn't a button or anything and select one of the Tile options (horizontal or vertical).