Had another occcassion today to compare two different drives (external USB) to clean up redundant data and reclaim limited space. Popping back and forth between two open windows partially covered on your screen is so “old school”. The same goes for having a single instance of Windows Explorer and trying to scroll up and down comparing contents. Enter the brave new era of Windows 7!
Place your mouse in the header of your Windows Explorer, left-click and hold the button while you drag the window to the far left (or right) or your screen. When you see a “shadow” of your window appear behind your selected window, release the mouse and you will have a window occupying the left half of your screen. Repeat the same procedure on another open window, moving it to the opposite side of your screen. You will end up with a side-by-side view that will be easy to move between and compare data in both views.