Error Message:

The quorum resource was not found. The Cluster service has terminated.

Explanation:

This is an unusual condition that can result when the database has been modified. In the registry, the Resources subkey identifies the Quorum resource object by a given string, but after loading resources, Cluster service cannot find that string. This means either the subkey was deleted from the registry, or the database is corrupted.

User Action:

Reinstall Cluster service.