I have been trying to fix this problem for months. Originally the screen was full size than is became smaller about ¾ of the size it should be. It is ¾ size as soon as the unit is turned on even during the HP start up and before XP is loaded.
One day the screen went back to full size and at that time I checked the control panel and the settings in both display and system (device manager) said Plug and Play monitor. Before that it would say something like 1430 x 760 flat panel. Once the unit was turned off and back on it went back to 1430 x 760 and the screen went back to ¾ size.
I have done the following and it does not help. Reinstalled Windows XP, down loaded the video driver and BIOS from HP site. I have manual changed the settings to Plug and Play monitor which fixed the problem for three times of turning the unit on and off. Then the next day it went back to ¾ screen size. Right now the Display and device manager say Plug and Play monitor but the screen is stuck at ¾ size.
Could it be something stuck in the CMOS BIOS? I have used the utility to set the BIOS back to factory setting and that has not helped. Would disconnecting the BIOS battery help to more completely clear out the BIOS?