My Gateway notebook does the same thing. However, I find if I pull the USB plug out when I power up, it will startup normally. Once you get to the Welcome screen you can plug it back in.
I have sent it to Gateway for repair and they say they just reset the CMOS but it still happens when at home. I'm guessing they can't repeat the problem there because there is nothing plugged into the USB port when I send it in.
This popped up after upgrading to SP2 and installing the newest version 2005 of Norton. Could they be doing it? I have no idea and I'm too lazy to troubleshoot now that I know all I have to do is unplug the USB on intial startup.
My USB plug goes to a USB hub with a scanner, a printer, a memory card reader and a zip drive plugged in. Maybe my laptop doesn't have the huevos to boot all those devices so thats why it stops.
Anyway, give that a shot on your laptop if you have USB devices plugged into it.
When you said HP, you said it all. Our prayers are with you.
Problem 1 sounds like a CPU/motherboard/Memory problem. If you have "extra" memory in it, usually it's found on the bottom in a tiny little door lid with a screw. Remove the extra memory. Remove any peripherals, take the battery out and just use the AC power. Take out the cdrom/floppy if it's in there. Remover any pcmcia cards. See what happens.
Problem 2, yes you can remove the drive from the enclosure in MOST situations. Usually it's simply just a standard drive with clamshell and interface.
Problem 3, I would take the drive out and hook it onto an IDE chain like a standard drive. sounds like the boot record is corrupted.
bttt