I have an HP Pavilion A1000N. When I boot it, it gets stuck at the HP screen, before bios I think (where you can hit F10 to restore or Fsomething for setup). If I power back down, unplug it from the wall for 10 seconds and reboot, it boots up fine and runs fine all day. So, I shut down at night. In the morning I have to unplug it for 10 seconds to boot up properly (or it freezes). If I add new software and the computer has to Restart, Restart is not a problem. Any idea? Power supply? Something strange and funky?

Have you tried booting the PC without the HDD connected to see if it boots quicker, HP/Compaq had various issues with Fujitsu HDDs and these do not spin up quickly enough as they get older and then fail the POST , when trying to boot a few times the drive tends to pick up its spin speed and is detected and boots pretty easily after that. If that is the problem you may need to swap the HDD, if not please reply back and i will check notes on the model for you.