Windows 7 moves/resizes windows on monitor power cycle

So,  4 1/2 years later Windows 8.1 still has the same bug that I saw in Vista!

But - great work Micheal - your fix still works.

Many thanks!

Thanks Mr Tompkins, reading this post, ive read the whole thread, helped me fix my problem, I had loads of entries in the registry for the simulated monitor, even with a fresh install of win7. I was doing all the reg editing and getting somewhere then eureka! So I'm posting this incase it helps someone else with a similar problem. I did a clean install on a pc i am selling, i set it up on a KVM switch with my main pc. My monitor is an old 26" samsung TV connected via VGA, everything went fine until i installed the intel HD GFX drivers, after a reboot i had 'mode not suported'. I entered safe mode with networking and installed TeamViewer, rebooted and connected to the problem pc, it had set its display to something really low, outside the tv's range, (this was evident in the reg) bingo I thought, changed it to 1366x768 on the desktop and switched back on the KVM, hey presto I had my desktop back....... for 5 seconds! This just kept happening, after reg editing i got it to work on 12 something but i lost 1366x768 as an option. After remembering your post I wondered if the problem had been caused by me switching over on the KVM while windows installed hense it thinking it was headless, I did another clean install and I didnt switch over to the main pc until it was finished. I checked the reg and there was now only one entry in the simulated monitor, this was now 1024x768 instead of the 480 something that was there before. I have updated the HD GFX and it is now running perfectly at 1366x768, I realise this isnt the same problem as others here but this thread helped me so I thought I would post my issue.

YES, YES, YES - thank you very much Michael. A very annoying problem solved.

My problem was not completly as described. I have a two monitor setup and almost everytime I awoke the monitors the open windows would show up as I left them, but only for a second or two, then all windows were moved to the monitor to the left and sometimes the windows were also resized.

MrFuzzums instructions solved the problem.

PrimSurfSize.cx to 1650

PrimSurfSize.cy to 1050

ActiveSize.cx to 1650

ActiveSize.cy to 1050

on both SIMULATE keys.

To Microsoft

I think you will help alot of your customers by solving these automatic resizing/moving of windows.

Who'd have thought that a 4-year-old thread filled with laments from users all struggling with the same problem would still turn out to be current and helpful?  Maybe it's part of Microsoft's strategy to just ignore these problems, and let the user community muddle its way through to answers.  

Anyway, when I migrated from a five-year-old PC running under Win8.1 to a new one under the same OS, I started having this problem.  I was surprised because I had never had the issue on my old machine (which began life as a Win7 box).  The first answer that I found in multiple places was to enable "Prevent windows from being automatically rearranged when moved to the edge of the screen" in the Control Panel.    No help -- every time I came out of hibernation, all windows were still moved to the northwest corner of the screen and re-sized.  

Then I worked my way through this thread and found the graphics configuration registry key fix.  In my case, the registry contained some ten different keys, with a seemingly random set of different  configurations.  But the last key in the list was the only one with the correct setting of 1920x1080.  So I kept that key, changed the SIMULATED key to 1920x1080, and, after exporting the registry just in case, deleted everything else.  

After a reboot, I still have only the two configuration keys, and all seems to be working splendidly. If I'm lucky, this will be the last of the obscure MS gotcha's that I'll have to track down to get the new machine working the way I want.  But I'm not counting on that.