Black screen’s root cause identified

Today I’m delight to announce that mysterious black screen bug can finally be solved thanks to Alex Ong. Click read more to see what he wrote and see Rafael’s answer.

“To Rafael and Windows X,

I think you guys will know all too well about the infamous black screen issues that occur when you install Windows updates, or after you uninstall a Uxtheme patch. On UxStyle, this also occurs when you boot into Safe Mode. Well, I have very likely found the solution to the problem.

The root cause of the black screen problems has to do with a setting in the Registry at HKEY_USERS\.DEFAULT\Software\Microsoft\Windows\CurrentVersion\ThemeManager. When you apply a custom theme, the setting of DllName changes to the theme you have applied. If at logon, for whatever reason (unpatched system files, the UxStyle service not running, etc.) Windows is unable to properly apply this theme, the black screen occurs.

My suspicion is that, at the logon screen, without the patched system files (or the UxStyle service running, when either you have uninstalled it or when you are in Safe Mode), Windows gets stuck in a loop trying, and failing, to use the custom theme.

The solution is to change the DllName Registry setting under HKEY_USERS\.DEFAULT\Software\Microsoft\Windows\CurrentVersion\ThemeManager back to the default, SystemRoot\resources\themes\Aero\Aero.msstyles. This applies when you are uninstalling UxStyle or restoring the system files to their originals, and when using UxStylem when booting into Safe Mode.

I have uploaded a Registry file containing the file containing the fixes to my Dropbox account: https://dl.dropboxusercontent.com/u/3668949/Uxtheme%20Black%20Screen%20Fix.reg

I have also posted the solution to the issue for those computers that are already stuck, at http://pixelfuckers.org/forums/5/topics/92 and http://comments.deviantart.com/14/3353886/3453308490

I believe a more permanent fix for this issue, is to have installers that manually patch the system files to both set the Windows theme back to default, and set the Registry value to the correct one upon uninstalling. For UxStyle, perhaps a solution is to write the default value to this Registry setting at every logon and logoff. 

On a slightly related note: Rafael, your UxStyle seems to break the new Windows 8 Choose Default Program dialog as well – if you choose an app under More Options > Look for another app on this PC, the app will not open until you kill and restart the Explorer process.

I hope you all found this email useful.

Regards,

Alex Ong
Also known as eXAKR”

Here’s what Rafael answered.

“Thanks for the note.
 
I’ll modify the installer to add UxStyle to safe mode boot and revert theme changes at uninstall.
 
Will put this fix in tonight, thanks. Stay tuned.
 
/rafael”

Looks like we’ll have black screen issue fixed by tonight. I’ll update all related works as soon as possible.