The NI service locator is a service that runs in the background and generally does not require user interaction. Nonetheless, it can be manually started when this warning shows up. Follow these steps to accomplish that:
1. Go to Start Menu
-> Windows Administrative Tools
2. Scroll down and locate NI Service Locator.
3. Right click on it and select Start
4. Try opening an example again.
If the NI Service Locator is missing in the list of services please follow the indications provided in Why Is There No "NI Service Locator" Entry in My List of Services?