Dave
Please try the suggestion below to see if we can restore Event Viewer.
Boot the computer to safe mode and open Windows Explorer (keyboard shortcut Win+E). Follow the file path C>Windows>System32>LogFiles>WMI and delete the RtBackup folder. Restart your computer and check whether the Windows Event Log service is now running. The system automatically recreates a fresh copy of the RtBackup folder.
You can access safe mode from normal mode by selecting Start, Run, type msconfig and press the ENTER key. Click the Boot tab and check the box before Safe boot, click on Apply and OK and restart your computer.
To revert to normal mode you follow the same procedure except that you uncheck the box before Safe boot.
Please change this service setting. Click on the Start button and select Control Panel, Administrative Tools, Services. Locate Windows Event Collector in the list. Check that it has started and that the StartUp type is Automatic (delayed Start). If it is not set to Automatic (Delayed Start), right click and select Properties, General tab. There is a box after StartUp type. The options are available on a drop down by clicking on the arrow down to the right of the box. Make the change and click on Apply and OK. Restart the computer and check whether it has started.