Someone came to me with a computer that was not able to run Windows Update. It could not even check for new updates. Also, upon booting, the system would get an error notification: “Windows could not connect to the System Event Notification Service service.”
I had to go to the System Event Log and clear the log (I received a “corrupted” error when trying to view it.)
After that I tried windows update and got the same error. But now in the system event log I saw a “file not found” error for TrustedInstaller.
The following fix from Darrell Gorter (his second post regarding how to replace TrustedInstaller.exe) worked:
After following his instructions I found the latest copy of TrustedInstaller.exe and was able to move it into C:\windows\servicing\
May also be important to note that this computer was also using Avast! which is mentioned in the post.