Windows 8.1 Lock screen issues

I uninstalled a few programs from our computer lab Dell 9030 All-In-Ones, but unfortunately after rebooting the machines post uninstall the Windows 8.1 lockscreen is broken.

We have in place Domain level GPO's being applied to the OU that the computers in the lab reside in which "Force a specific default lock screen image" and "prevent changing lock screen image". This GPO is being enforced, and it is also redundantly set on each computer's local group policy.

I have ran gpupdate.exe /force then shutdown -r -t 00 many times but still cannot force the settings on the machine.

I went to the server and disabled the two specific gpo's, and also disabled the two local gpo's respectively to no avail.

With the GPO settings set to disabled and logged in as the Administrator I can select the default images Windows supplies, but no matter what I select no image is applied.

Specifically, after boot the interactive logon message is displayed, and once "Ok" is selected by any user, a blank screen appears. I suppose this blank screen that is the color of Administrators selected background color should be the lock screen. To move to the Windows login screen, one must hit the return key approximately 5-10 times before the login screen will appear. Hitting the return key once and waiting over 5 minutes will not allow access to logon screen.

If the interactive logon message is, "Ok'ed" and the blank screen is left to sit there for an extended period of time, eventually the Microsoft.Time & Microsoft.Date animation will appear to correctly display the current time and date for the machine (making me believe that this blank screen is in fact the lock screen.)

I have then gpupdate.exe /force the machines and restarted many times on the machine to no avail.

Back on a test few machines(8) I have set the local group policy to "Do not Display the lock Screen", hoping that would take care of the problem.

This has not worked, and I have updated the GPO settings again many times.

I assumed with preventing the lock screen each machine would go from the interactive logon message to the login screen once Ok'ed, but that isn't the case.

Starting a test computer in safe mode, I was able to add a registry key under, HKLM\SOFTWARE\Policies\Microsoft\Windows\Personalization which was "NoLockScreen" DWORD=0x00000001

After rebooting a few times the machine still has the blank blue screen between the interactive logon message and the logon screen, and you still have to hit return 5-10 times for the login screen to appear.

I would like the lock screen to work, my supervisor has a special .png deployed for the department, but I would rather not have any lock screen and go straight from the interactive user message to the login screen rather than this blank blue screen that users will have to un-intuitively hit return 5-10 times.

I'm stuck. Is there anything else I should look at or look for?

I've also backed up the registry, and cleaned it the CCleaner a few times, but to no avail (before and after adding the registry key.)

The only additional thing to note is that since the problem began, the interactive logon message and "Ok" button takes a little bit to show up on the computer. Post boot it takes anywhere from 30-45 seconds for the message to show up, and then a little longer for the button to appear.

Any help or suggestions would be greatly appreciated.

Update 8/25/2015 9:45 PM On at least one of the computers, it seems that the lock screen and login screen has merged into one. (To my knowledge the time and date animation should only be on the lock screen, not the login screen.)