utc.privacy.diffbase

Diagnostics baseline data

A .diffbase file contains baseline data of the Windows diagnostics framework. The known file is utc.privacy.diffbase in the DiagTrack directory of Windows. The Connected User Experiences and Telemetry service compares current diagnostic settings and events against this base. The file is binary and not for manual use. Windows maintains it automatically.

A file extension is only a part of the file name. It does not give a guarantee about the format or the content of a file. But on Windows, the extension selects the program that opens the file.