Windows are resized and moved after waking PC.

Problem:
Windows 10 windows resized and moved after waking from sleep/monitor power save mode.
I build this PC last week and even after updating everything and problem remained.

So in the tradition of Mac Manager LISTSERV (RIP) of posting a "SUMMERY" of solution found for a problem. Here is my contribution to that tradition, which should be revived in this type of forum.

Research:
After hunting for solution, found many from people having you perform actions that don't do anything but waste your time. None of the posted solutions worked to resolve, except work a rounds that really didn't address the cause and have users perform an action before they walk away from PC. What lead me to the solution is an old post from 2010 for Win7 from MichaelAtOz on MS support pages.

Analysis:
What's happening is the monitor goes into power save mode since the PC turns of the monitor. Thus providing the monitor with no signal activating power saving of the monitor. MS Win10 then creates a dummy monitor registry for sleep/monitor off mode, but with the wrong values. I believe these values are generated by Win10 from the lock screen app, but MS would know that and should correct that incorrect registry value being created.

Solution:
This is on a PC with only one 4k monitor. So, I can not confirm for multi monitor systems (see "Multi-Monitor" below for a possible solution). What needs to be done is to make the Registry setting the same for dummy monitor registry.
Steps:
0) Shut down system and turn off monitor. Disconnect power cord from PC and from monitor and monitor cable to PC for more than 30 seconds. Reattach everything and boot up PC. (This step may not be necessary, but I had been done before next step.)
1) Open Registry Editor (as admin) to the following path:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\GraphicsDrivers\Configuration\
2) Delete all entries in this path (there should be at least two) Delete by clicking on item and press "Delete" and confirm if needed. Exit Registry Editor (File - Exit) and restart PC.
3) After system start/login open Registry Editor (as admin) to the following path:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\GraphicsDrivers\Configuration\
There should now one be one registry entry (don't let your PC goto screen saver/sleep). Click on tree arrow, then click on tree second arrow to view values. By clicking on each 00 the values will be displayed on the right side of Registry Editor.
> GSMxxxxxxxxx (this registry entry is the monitor connected, the text will vary)
> 00
|- 00
4) Record all the values of this registry I made a screen shot with snipping tool of the values for both 00 sets and save to desktop. save one as 00 and other inside the 00 as 00-00. Exit the Registry Editor (File - Exit)
5) Allow PC to go into power save mode where is gets no signal and wake system.
6) Change value in dummy monitor registry to match real monitor. All values must match.
Open Registry Editor (as admin) to the following path: (it may auto open to path)
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\GraphicsDrivers\Configuration\
You will see a second entry now, this is the dummy monitor entry.
> NOEDID_xxxxxxxxxxxxxx (maybe named different)
You need to change all the values in both 00 entries to match the original entries. Use the screen caps to copy values. Double click on the value that needs to be changed, make sure that change the "Base" of he value to "Decimal" after all changes have been made Exit the Registry Editor (File - Exit) and restart.
7) Verify fix. Log in and allow PC to activate monitor power save mode and wake system.

Multi-Monitor System
If you have a multi monitor system adding back each monitor one at a time may work. Have each monitor unplugged from PC then add back and perform registry edit above one at a time. On boot up confirm that windows don't change on wakening system and add another after shutdown until all monitors are attached.

Question:
Now that the cause of this problem has been found (Win10 creating a dummy monitor registry entry with the incorrect setting of the actual connected monitor to act as a place holder for sleep settings) when will a correction be made by Microsoft so users won't have to manually edit the registry to correct this problem?



My PC Specs:
Intel i5 8400 (using on CPU Intel UHD Graphics 630)
ASRock H370M-ITX
RAM 16gb
Samsung SSD - Window10 Boot
Tosh x300 4TB HHD - Data
Win10 Home 64bit
Monitor - LG 27UD58B - connected using DisplayPort with LG supplied cable.
running at 3840 x 2160 scaled at "Recommended" 150%

bro67 said:

I have never had to edit the registry for monitor settings. Sounds more like a driver/GPU software issue, since these are rarely windows issues.

what iv learned about this issue for the past few years is this...
yes its drivers - but it's also windows and monitor hardware... so one side fix may not be the entire answer.
the only way i've been able to solve the issue is with a "deadhead" or dummy plug with an output to a real monitor.
if you do a search for - Virtual Display Adapter HDMI EDID Dummy Plug - you'll get your fix.
a small simple plug that goes in line with the monitor plug and keeps the "line" alive even when the monitor goes off / gets unplugged or otherwise.
in my scenario everything worked fine until i awoke my screens (i have 5 on my setup) and one would be "re-found" every time, and reset my window positions...after the plug everything works perfect.

they sell for as high as $20 each but i found them on e-Bay for under $10. with many options for what plug type needed - vga, hdmi, dvi, displayport.

hope this helps someone as iv been dealing with it for years and finally can sleep at night knowing my powersave is working...lol

vagrant tech said:

the only way i've been able to solve the issue is with a "deadhead" or dummy plug with an output to a real monitor.
if you do a search for - Virtual Display Adapter HDMI EDID Dummy Plug - you'll get your fix.

Could you please elaborate on what does it do? I have the same problem on Windows 7. In fact, on Windows 10 I do not have this problem (on the latest build everything works) and I am interested in emulating this behavior on Windows 7.

I disagree with the posters above - this is not really a hardware issue. I have the exact same hardware on a dual boot machine and I do have this problem on Windows 7 and not on Windows 10.

unifex said:

Could you please elaborate on what does it do? I have the same problem on Windows 7. In fact, on Windows 10 I do not have this problem (on the latest build everything works) and I am interested in emulating this behavior on Windows 7.

I disagree with the posters above - this is not really a hardware issue. I have the exact same hardware on a dual boot machine and I do have this problem on Windows 7 and not on Windows 10.

what the unit does is emulate "fake" that a monitor is hooked up and let a real monitor signal pass through.
it solves the issue of when the system wakes from sleep mode or monitors wake from sleep, the monitors actually showed as disconnected and the computer sees the monitor as a new device and resets all the windows accordingly. this unit stops that from happening by not letting the computer think a new device has been added.

in short terms it's like the monitor never went to sleep so it does not disconnect and reset window settings.
and yes it is a bit of hardware but is is ALSO drivers AND windows system...
iv had this issue with 7 for a bit and when i went to 10 it went away for months and then reappeared after windows update...went away after driver update and came back a few months later...so ya iv been fighting this issue for years... and iv seen it in both and then on some not an issue... HEAD SCRATCHER.