Monitor Identity Issue

Mike99 · 31 Jan 2017

I’m having issues with Windows 7 changing monitor Identity numbers when a second monitor is connected. This a creating a problem with images being displayed on the wrong monitor. It didn’t used to be that way until I installed a new HDD with a fresh copy of Windows 7. I don’t recall if the Identities changed before, but there never was problem before.

Did a lot of Googling & just about everything says you cannot change the Identity number. However some people appear to have had some degree of luck by deleting some Registry entries. It appears Windows creates entries in the order in which the monitors were initially connected & remembers that order. Or words to that effect.

I’ve seen a few different approaches involving deleting some Registry entries. I‘m not sure which one to use and how much data to delete.

1) Go to the registry & find the monitors and delete them in the enumeration.
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Enum\D ISPLAY

2) Open Regedit & delete the DISPLAY key. HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Enum\DISPLAY

3) Delete these two registry keys, and then add the monitors one at a time.
HKEY_LOCAL_MACHINE\Systems\CurrentControlSet\Control\GraphicsDrivers\Configuration
HKEY_LOCAL_MACHINE\Systems\CurrentControlSet\Control\GraphicsDrivers\Connectivity

4) One comment mentions all 3 of the above keys but didn’t elaborate on what to do.

Does anyone have any experience with doing this?
Any suggestions if I should delete entries from the DISPLAY key and/or the Configuration & Connectivity keys, and if all the entries in those keys should be deleted?

Any comments would be greatly appreciated.
Thank you.

ICIT2LOL · 01 Feb 2017

Mike your system specs are rather sketchy in that there is no info on what graphics there is in the machine. I myself cannot for example look up the model of the machine and that makes it very hard to see exactly what there is inside.

Now just out of curiosity how many graphical outputs are you using - two from one card?? You may appreciate it is very hard to advise if we do not know that sort of info. However assuming there are two DVI or VGA sockets on that board/card and not wanting to sound flippant have you tried swapping the monitor cables from one to the other??

Mike99 · 01 Feb 2017

I wasn't sure which section to post this in.

I running Windows 7 64 bit Ultimate and a GeForce GTX 750 Ti SC video card.

Usually I use just one monitor but sometimes connect a second one. The main display is either a 23" or 27". the secondary is a 19". I never had a problem when connecting the 19' with either the 23" or the 27". That is until I installed a new HDD with a fresh OS and some software. Now the 19" & 27" combo has an issue with both images being displayed on the 27" unless I change some settings in the software (Visual Pinball). Again I never had to do this before.

As mentioned I don’t recall if the monitor Identities changed before, but there never was problem before. Perhaps it's related to how Windows "remembers" the initial sequence in which monitors are connected. I figured if I could reset the part of the Registry that holds that information then I could try connecting the monitors again. I'd have nothing to lose & possibly something to gain.

Anak · 01 Feb 2017

Hi,

Found this: https://Reset graphics and monitor registry settings | social.technet.microsoft.com/Forums

There is an old (5years) w7 thread on how one member did what you want to do: Reset display settings for a monitor that is not plugged in?

There is more here: reset the part of the Registry that has monitor settings | google search, and here: reset display settings windows 7 registry | google search

Mike99 · 01 Feb 2017

Thank for the links. I've seen some of those but not all of them. Every bit helps. Thanks.

It appears the most popular method is to delete these two registry keys & then add the monitors one at a time, which I did.
HKEY_LOCAL_MACHINE\Systems\CurrentControlSet\Control\GraphicsDrivers\Configuration
HKEY_LOCAL_MACHINE\Systems\CurrentControlSet\Control\GraphicsDrivers\Connectivity

New keys were created but it made no difference. The PC boots up with the main monitor having the desktop so I'm presuming everything is OK according to Windows. Yet somehow the software (Visual Pinball) treats the monitors differently, but how would it know they are different? I'm going to try the newest video driver & see how that works.

ICIT2LOL · 01 Feb 2017

Ok Mike now just for the future it is always a good idea to back up the registry before you make any changes to it for two reasons in my book anyway and that is if you accidentally delete an entry of any sort or have issues after doing that then it is a simple process to reinstate the entries deleted.

If the entries I am deleting are reasonably important to the system then the saved file I name REGEDIT and the date so that I know exactly when the reg was changed the backup takes up no space to mention and is very simple and quick to do. So for teh sake of doing that you risk having to do a repair install or worse a total clean install.
Registry - Backup and Restore

Anyway lets see what happens with the new driver.

Mike99 · 01 Feb 2017

I created a restore point & backed up the registry before deleting the keys.

I installed the new driver but it made no difference.

I'm going to see if there are any problems about installing an earlier version of the software.

ICIT2LOL · 01 Feb 2017

Now actually you are a jump ahead of me - the next thing I was going to suggest was get an older version of the driver as the latest one could have bugs that your machine isn't compatible with.