inspiron 1525 no boot devices found

Started not finding boot devices one day.

tried a reinstall of vista home basic from a microsoft disc(not dell) so no drivers or anything

Did an install like any other computer, went on the website with another computer and downloaded wifi and internet drivers

installed them without an issue. Install all updates. says to reboot. ok.

Then when it reboots it says the boot device cannot be found.

Hard drive shows up in bios

if the vista disc is in the dvd drive, windows will boot after it asks to press a button to boot from disc and i dont press anything

if i press the media button, (one with the house on it) it will boot normally after showing the medialink screen or whatever that is called.

i still have the original hard drive as i thought it was no good and didn't bother checking it.

Did i miss something that it won't recognize the boot sector on a normal restart or boot up.

if it makes a difference it can be put into sleep mode and come out fine.

any help with this issue would be appreciated

thanks