HFSS15: Setting or Removing Temporary Directory Values in Configuration Files:

The UpdateRegistry command line tool, described above, may be used to view, add, change or remove the Temporary Directory setting from any of the Temporary Directory config files. The registry key for viewing or modifying the Temporary Directory is TempDirectory. The -Get, -Set, and -Delete options are valid for viewing a Temporary Directory setting, adding or changing a Temporary Directory setting, or deleting a Temporary Directory setting. The -GetKeys option does not list the Temporary Directory key.