Got one for free, thank you.
But it had power-on password set.
To get it removed:
1 ) find the manual on hp.com
2 ) remove battery pack
3 ) remove cover over extra memory
4 ) remove the RTC battery
5 ) Wait a couple of minutes
6 ) Start the PC on power only (no RTC and no battery pack)
7 ) When you get the error about the hard disk turn off
8 ) turn on again. Password gone
9 ) put RTC battery back, and place cover, add battery pack