Black Screen of death after login

My windows 10 laptop recently failed to boot after login. It cannot be fixed using system restore as it fails to identify any previous restore points. I have identified where the potential error is coming from.

I can access CMD using the shift + restart to access troubleshooting. Through this I used run to get into regedit.
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon shell was giving a value of "cmd.exe /k start cmd.exe" instead of "explorer.exe" if I try to reset it back to explorer it will fail to start and the entry will have been reset to "cmd.exe /k start cmd.exe" .
Any help on how to fix this issue would be appreciated as it is way over my head.

Thanks

 

So maybe something is wrong with explorer.exe . Try a 'sfc /scannow'

 

I have tried a number of commands to try and reset my registry and or fix the hard drive, including bootrec and chkdsk commands that have done their job for over a day scanning the harddrive for bad sectors. I now try to boot my system and get the following error. "Shellhelper.exe - Application error. The exception unknown software exception (0xe0434352) occured in the application at location 0x000000007673DDC2)" and nothing else will load. Ctrl + Alt + Delete has no output. Don't know the following steps I should take to fix.

 

Do you have program called 'Microsoft Private Folder'? Go to the sign in screen where you put in the password and right click on power icon and press press shift restart. This should get you into Safe Mode. Then go to Control Panel > Programs and Features and uninstall that program.