Files with hpd extension were used by Hewlett-Packard's developed applications. They are no more used in present.
There is one other file type using
the HPD file extension!
.hpd - HotDocs PDF document
HPD file extension - HP document
What is hpd file? How to open hpd files?
File type specification:
File extension hpd was also for some kind of document format in applications developed by Hewlett-Packard producer of computers, printers, servers, laptops etc.
It is probably obsolete file format, not used in present HP applications.