Won't boot past HP boot screen

[mmk412]

When I start my HP Pavilion m9200t (6GB RAM) it starts and takes me to the HP boot screen and then stops. When it first starts the keyboard lights up once then nothing. If I try to hit any of the options (ESC, F9, F10, F11) nothing happens. If I hold the ESC or F10 key when I turn it on I see "Boot Menu Loading" or "Entering Setup" but it never does go to the boot menu or setup screen. This just happened out of the blue. I've tried most of the solutions that I've read about but nothing seems to be working. The following is what I've tried:
     1.   Changed keyboards.
     2.   Removed all peripherals except keyboard, mouse, and monitor.
     3.   Removed all my RAM modules and tried starting the system with each module inserted one at a time.
     4.   Disconnected the Hard Drive and re-connected. Made sure all connections were tight.
I did get it to work one time after removing the RAM and reinstalling it.  When I was able to load the system that time I did a chk disk and everything was ok. Thinking everything was ok I shut it down and when I tried to boot back up I got the same problem. I've pulled all the ram again and reinserted it but it doesn't work.
What I'm not sure of is is the setup menu on the hard drive or is it on the motherboard in the CMOS???   The only solutions that I've seen so far is to replace the hard drive or the motherboard. I sure don't want to change the motherboard and I don't want to spend money on a new hard drive if I don't have to. The computer is four years old. It came with Windows Vista x64. I upgraded to Windows 7 x64 about a year ago. Any help would be appreciated. Thanks

Mike

[CherylG]

Try unplugging the cable to the hdd and attempt boot. Can you enter BIOS setup by tapping F10 key? A bad hdd 'can' cause the symptoms you are having. If the machine boots and enters BIOS setup without the hdd..that would be the part I replaced.