Hello,
I have written a desktop replacement shell using Microsoft Visual Studio 2012, C#, .NET 4 and WPF. The installer for my shell sets everything up for it to be the shell of choice by modifying the registry key:
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\Winlogon\Shell
This works great EVERY time!
My shell is meant to be used with everyday apps. When someone needs to perform administrative tasks, he or she simply exits the shell, and the normal Windows Explorer desktop shell loads.
To accomplish this, when the user begins the process of exiting, I have code that:
(1) modifies the Shell registry key to "explorer.exe"
(2) then starts a new System.Diagnostics.Process for "userinit.exe" (also have tried just calling "explorer.exe")
(3) then resets the Shell registry key back to my app (for the next time someone logs in)
(4) then finally, exits my app ( via Application.Current.Shutdown(); Environment.Exit(0); )
This works great most of the time. The Windows Explorer desktop shell loads, and then my shell exits just after that. The end result is as if Windows Explorer had the been the shell all-along.
HOWEVER, in about 1 of every 4 times, seemingly for some unexplainable reason, Windows Explorer only launches as an app, WITHOUT the shell! This results in the user being left with no shell at all, only the Windows Explorer application.
For a long time I have tried and tried to figure this out, with no success!!! I have tried adding various amounts of wait time ( via Thread.Sleep([milliseconds]); ) in my code, all in different combinations and at different places in the four
steps above. But still I am unable to reason what is going on here. This problem occurs when using Administrator user accounts, so registry key permissions are not in question.
WHY would Windows Explorer EVER launch in "regular" app mode when it is configured as the OS shell? And why does there seem to be no observable pattern to this?
Does anyone have any ideas about what is causing this? Or more important, does anyone know how I can fix this?
Thanks!