WMI (Windows Management Instrumentation) is a framework for managing Windows systems. It includes components like a repository, namespaces, classes, objects, and methods. WMI was introduced in Windows 2000 and is used for tasks like retrieving installed applications, adding users to groups, and rebooting computers remotely. It can be explored using tools like WMI Control and WBEMTest. Issues with WMI can be troubleshooted by checking error codes, logs, and using tools like WMIDiag to check health. Potential fixes include re-registering WMI modules, recompiling MOF files, and rebuilding the WMI repository as a last resort.