At work, we've been working with the HP t55xx series thin-clients, mainly for one of our customers.
This article contains some things we've found to be very useful. It is not a real howto, but rather a collection of smaller items, telling you how to do certain things, and those things are not easy to find in the manuals.

There are 4 ways to reset a t5530 to factory defaults:

Open Control Panel, open the System applet, then click on the button that says Reset. When powered off, press and hold the F9 key on your keyboard, then power up the device, and keep it pressed, until the  ...