|Oh, OK. Yeah I wondered about that.|
If you didn't do a bios update or make other changes there then it's probably not a bios issue, although there's usually an option there to revert to 'bios defaults'. You could try that and see if it makes any difference.
Does linux have a boot menu of safe mode-type boot option? Or if the windows 7 install went OK try safe mode from the windows F8 boot menu.
Most PCs will give a single beep on the completion of a successful post just before the OS start to load. Assuming your HP is the same then not having that beep would be bad. Were you inside the case at all? If so, retrace your steps checking that all cables and cards are firmly attached.
If it was a hard drive problem I'd expect an error to show up but you might temporarily disconnect the hard drive and see if you get the normal messages for that situation.
Oh, and when you're in the case make sure the power cord is removed--not because you might get shocked but because most power supplies provide a small charge even when the computer is off and removing or installing hardware to a 'live' board can cause hardware failure.
Don't forget to preorder your Hatch green chili for this fall. Many vendors ship world-wide.