Windows 7 Dual Monitors - Turning off a monitor causes desktop to rearrange resulting in significant amounts of lost productivity.

I have reviewed this list of gripes, rants, and workarounds. This really is the fault of both Microsoft and hardware vendors. Microsoft Windows is all about ease of use. They place a great deal of emphasis on user-experience. So when people who aren't IT Professionals undock their computer the windows move seamlessly to the active window. So this is actually a "feature" than a technical failure. I've been in IT for over 24 years, so I believe I can say with some expertise that not having this feature would generate a greal deal more mayhem for all markets. Yet the manufacturers of the intelligent displays also made the fatal error of making their device show "always on" to their source regardless if they really are. 

Before I offer some suggestions, which I am currently testing, I want to say to those of you who taken to outright indecency in their posts to Microsoft agents on this thread. They're IT professionals like you and I. They aren't the engineers the did this, they're just left to support it the best they can. So for lack of a better term "back off". If you're an home consumer who's frustrated, there is no where in license agreement that says if you're not happy you can speak condescendingly to someone. I'd recommend you remember the rules of common decency still apply to people trying to help you, even on the internet. 

Now, so far I've only found a few workarounds, while I research this:

1. Click on the app in the taskbar that is on the wrong display. Press Windows logo key  + Shift + Left arrow or Right arrow (left or right of the  current display is relation to have you have them set up in the display settings).
2. Always update your video drivers. It's just good practice, and the manufacturer might have  implemented a solution. 
3. Make sure you're using the right display drivers for the specific MONITORS. So often people install their video card drivers and ignore the devices they plug in. It may be using the wrong driver, like a generic driver, which lacks the ability to properly detect an on/off state. Check with your display manufacturer for the current drivers. 
4. Someone here has written some open-source coded script to use to solve this issue. However, I haven't tested it. If you're not an IT professional with some understanding to review the code and understand the what it's doing, you install it at your own risk. 

So until MS corrects for this, or the manufacturers figure it our, this is what we've got until someone finds a permanent solution.

Good point about the low NVS 3D performance.  Not an issue for me.  Primary reason for this card in my case was standard office app use and low cost along with low profile form factor.  If 3D performance is needed, I suggest a card should be chosen that is optimum for the primary application it will service.

FYI - in general as video adapter performance and feature sets increase, so do all the associated things that make that possible.  Memory allocations, driver quirks, power demands, price of adapter, etc.

By the way, NVS-series of graphcs card are totally unfit for 3D.

Once, by an accident I ordered a computer with it and had to exchange because Autodesk Inventor (and SolidWorks) on a new machine looked horrendous comparing to a 4-year old machine with the same mfg. card (nVidia).

For real high-end and for 3D MANDATORY - use nVidia's other cards (GeForce for consumers, Kepler & beyond for professionals).

NVS card was only designed for 2D applications - business charting, line drawings/sketches, word processing, etc.  3D cards are GeForce cheap, and Kepler or higher - professional

I'm an IT guy.  I also find it ridiculous that this problem still persists after 6 years, but not surprising.  We can either complain to each other or find a solution.  While the "Motion Detect Killer" appears to be a consistent solution, I found a better solution that worked for me.

I used a DisplayPort to HDMI adapter cable to fix the problem.  (Amazon purchase.)  I have a Nvidia NVS 310 Displayport card feeding two DELL U2415 monitors.  This problem went away when I ditched the high quality DP cables and used the cheap DP -> HDMI adapter cables I also had available.

You'll know you fixed the problem when you power off the monitor and you don't hear Windows make the disconnect sound similar to when something is removed from a USB port.

Good luck!