A friend of mine installed my H470 (with bluetooth) on my Dell laptop. He set an access code...but forgot to tell me what it was. After deleting the printer by accident, I was never able to reinstall and connect the H470. Finally, with help from a "senior" tech at HP, I found out how to do the reset:
1) While holding down the green-lighted on-off switch,
2) press the "X" button FIUR times, and then
3) press the "down-arrow" button SIX times.
Then uninstall/reinstall the software. Can you believe this? Geez.

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic