My Windows 7 (64-bit) machine lost internet connectivity. Rebooting didn't help. On boot-up systray message would appear:
Failed to connect to a windows service. Windows could not connect to the System Event Notification Service service. This problem prevents limited users from logging on to the system. As an administrative user, you can review the System Event Log for details about why the service didn't respond.
Event Viewer just showed an error that the 'Event Log service is unavailable'. After trying to start it manually, I got:
Windows could not start the Windows Event Log service on Local computer. Error 1747: The authentication service is unknown
I have tried running a couple of virus scanners and malware removal programs, and doing the System File Checker command:
but there were no useful results.
Booting into safe-mode didn't make any difference.
System restore showed that there are no restore points, although the System restore was turned on on the machine.
I'd really like to not have to re-install the OS again.