I don't recall there being any "HP Docs partition"; instead, what I recall is an HP_TOOLS partition. Is that what you are talking about?
If so, the only way I recall to restore that is to do a complete factory reset of the PC, as this reformats the ENTIRE hard drive, recreates all the original partitions, and repopulates them.
To do this, you reboot the PC, pressing F11 repeatedly while doing this. When the HP Recovery Manager starts, you choose the option to reset the PC to factory conditions.
This takes easily a couple of hours to complete -- so you have to be patient.