This was on my neighbour's computer. I was trying to help them with their issues on an Acer desktop with Windows 10 64 bit. Their computer updated on the night before or early morning on October 1 and the update got stuck at 98%. After waiting hours and no movement, they rebooted. On trying to reboot, they would get errors like ctfmon.exe unknown hard error, sihost.exe unknown hard error, or the Desktop not being available. The system tray had an icon of a gold coloured lock.
There where no restore points. System restore was disabled. Microsoft in their great wisdom decided to disable system restore by default on Windows 10. Resetting otherwise is unavailable because it was impossible to get into the settings.
If I try a normal boot, I get the following error: C:\Windows\System32\config\systemprofile\Desktop is not accessible.
The desktop goes black along with the task bar and is almost completely useless. The start button / menu doesn't, all the icons are gone, it's impossible to use the notification area. The only thing that works is I can right click and open the Task Manager.
So I open Task Manager then clicked on File, then Run new task. I typed cmd in the Open field and checked the option to Create this task with administrative privileges.
Tried SFC /SCANNOW but it freezes at 48%. Desk check finished but didn't indicate any issues. Also safe mode doesn't work either. I also haven't been able to boot of any CD / DVD / Flash Drives. I've disable secure boot in the BIOS but still. If I try to boot of a DVD I get the message ...Press on any key to boot of the DVD... I do but the computer just reboots. I know the CD's and DVD's are good.
One suggested way to fix this issue was in the Run new task type in c:\users.
Before going any further you'll need to set your system to see hidden files:
To access some of these folders you will have to enable the option to see hidden files. In this case, in Task Manager I clicked on File, Run new task, then typed in explorer.exe to open up Windows Explorer or File Explorer I believe it's called in Windows 10.
Click on the Options icon on the right hand side of the top menu. If you don't see it click on the option View first.
Then in the box that opens, click on the View tab in in the Advanced settings: section towards the bottom, find the Hidden files and folders section. Check the option Show hidden files, folders, and drives and uncheck Hide protected operating system files (Recommended). I set my computers like this right from the beginning.
Then Apply and OK when done. Now you can see all the usually hidden system files. On your desktop you'll probably notice a couple of files called Desktop.ini. That's normal.
Once you type in c:\users, File explorer will open. Go into your user folder with your name on it and on the Desktop folder there, right click on it and go into properties. Then click on the Location tab and click on Restore Default.
Worth a shot but didn't work.
Another suggested option for fixing this was to replace the file from c:\users\Default\desktop to C:\Windows\system32\config\systemprofile\Desktop.
So go to File exlorer and navigate to C:\Users\Default\Desktop, right click on that Desktop folder and click on Copy
and then go to C:\Windows\system32\config\systemprofile, right click on the systemprofile folder and click paste.
Reboot or restart system. This didn't work. There was already a desktop folder there so I tried deleting it at first. Nothing. I checked the structure of this folder on my own system and was surprised to discover that there is no Desktop folder at that location on my system.
Another suggestion, I created a new profile and tried to boot into that, I had to use the command prompt for that.
I was able to right click on the taskbar and open the Task Manager. Then clicked on File then Run new task.
I typed in cmd, I also check the box that says Create this task with administrative privileges.. Then when the cmd window opens I typed in the following (note: put in the username for the account you want to create where it says usernamehere and the password you want to use for passwordhere):
net user /add usernamehere passwordhere
net localgroup administrators usernamehere /add
I then proceeded to try and log into that profile but no change.
The computer when turned on, it gets to the welcome screen, then a message comes up preparing windows. And this can go on and on and on. If it goes through it goes to a black desktop, all icons gone, taskbar and start menu almost completely dead.
I have some access to some programs by going through Task Manager. I was able to get through the control panel and tried to use the Backup and Restore options there but it led nowhere. In the Services tab in Task manger I noticed just about all of the services listed where stopped so I started right clicking on each one and then clicked on start, right down through the list. Restarted, no difference.
I noticed If I started up explorer.exe this way I get back the background picture, taskbar and start menu still dead except for Task Manager. And the icons reappear, some programs seem to work and even the Internet.
I already tried to boot of A DVD and Flash but couldn't so what I was going to do (it was getting late) was download the latest version of Windows 10 on a flash drive, waiting for the new October update, and I was going to try to reinstall Windows by running the setup from within windows.
The computer that they are using is a rented one from a company called EasyHome. So they where trying to get in touch with them to see what they could do. Return it for another one if nothing else.
So that night I used Microsoft's media creation tool: https://www.microsoft.com/en-us/software-download/windows10
You might want to wait, at the time of this writing, the October version of the update for Windows 10 has a few serious bugs including deleting personal documents. As I'm writing this the only update available now is the April 2018 update. Anyway go to their site and click on the Download tool now button.
Open it. Accept security prompts. It starts by Getting A Few Things Ready. Click on the Accept button to accept their license agreement. On the screen What do you want to do? click on Create installation media (USB flash drive, DVD, or ISO file) for another PC. Then click Next.
If you want to just upgrade from there leave it on the Upgrade this PC now option. Then you have the option to choose language, architecture, and edition. I left the language on English (United States), the Edition: Windows 10 and Architecture: both (just in case I have to use this to fix someones computer that might have either 32 or 64 bit) and I was planning to put it on a flash drive. Both would not fit on a standard DVD.
Choose your flash drive , it should automatically be selected. Click next. Then it will start downloading Windows 10 and will prepare your drive for you automatically after that. Just wait till it's finished. If you get an error message it can't finish format your USB flash drive first and try again. That usually clears it up for me.
The next morning before, I got a call from them, something had come up on their screen. Turns out it was the privacy option screen from the Windows install. They left their computer running overnight and it started updating. So I set all this options to turn off. And let the system update to see what would happen. This October update is no Saint either. It seems to have a habit of deleting personal documents, but right now it is the lesser of two evils in this case.
Sure enough, the computer is working properly again. Updates screwed it up and Updates fixed it. If you use Microsoft's tool now you'll get the April 2018 update not the October one. Warning this is a known problem with the April 2018 update as well. Happy Halloween. (insert evil laugh here)