Event Log ~ views Event Log messages from applications in Event Viewer. Always helpful to check out the Event Log to see what problems with applications are popping up that is "hidden" from the normal user. To see quickly what, if anything has resulted in your adjustments, you may consider clearing the Event Log. Windows Management Instrumentation also requires Event Log Service to be running. If you disable the Event Log Service, but do not disable Windows Management Instrumentation, your computer may have an extended boot time while Windows Management Instrumentation is waiting for the Event Log to start. It is just best to keep this service active.
Windows Management Instrumentation ~ this service is required if you want to see the "Dependencies" tab in service configuration and you want everything to go smoothly. I do not recommend disabling this service as strange things may start to happen.