What causes Black Screen of Death after Windows Update Failure on Windows 7 x64(0x80070057)

Receiving error 0x80070057 while performing Windows Updates on Windows 7 (64-bit).

Tried the following:

1. Ran Windows Update Troubleshooter. It fixed several Registry problems, but still reports a problem with the aforementioned code.





2. Start > Run > cmd > net start WSUSService - This fails with 'The service name is invalid'




3. Set the 'UseWUServer' registry key (located under HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\WindowsUpdate\AU) to 'dword:00000000' as per another SuperUser post.




4. Reboot. Now, I no longer get an error message when I run WinUp but it does not succeed, and gives no error message.




5. Applied microsoft.com/en-us/download/details.aspx?id=20858 - would not download UNTIL I DISABLED PEER BLOCK peerblock.com Once applied and rebooted, the downloads came tumbling in!




6. After updates applied, now I have a Black Screen of Death on reboot. Restart, go to Safe Mode which prompts for Recovery. After recovery, it hangs on an AVG antivirus DLL.




7. Get into Safe Mode again by persistence, found Explorer.exe was crashing. Ctrl-Alt-Esc didn't work, but by persistence with repeatedly restarting Explorer.exe from Ctrl-Alt-Del and Task Manager, I noticed BatteryBar was launching immediately before Explorer failed, and after removing BatteryBar's files under C:\Program Files\ I was able to restart without Safe Mode.

Applied Important and Critical updates with Windows Update, Black SOD returns. Rewind with multiple System Restores, going very slowly on Windows Update now.

Any idea of how I can determine which update causes the problem?

If there are log files, where would I find the useful ones?

Which are they?

What do I look for?