File Extension KMZ

File type: A Zipped KML file

About the KMZ file type:

If Windows cannot find the appropriate program associated with .KMZ files, then your registry may have errors. Check your Windows registry for errors (includes file association errors).

KML stands for keyhole markup language which is an XML based language used in a range of 3D geo-spatial software used to support Google Earth. The KMZ file specifically is a bookmark file that will return you to a specific saved view of the Earth. This file can be unzipped using a normal unzip package, although it would normally be viewed using Google Earth.