Also, I cannot find my Vista DVD
. I'm not sure how to tell if the hard drive is recognized in the BIOS
The purpose of checking in the BIOS is to ensure that the HDD is recognised and that it is listed as a boot priority device
Albeit I completely concur with my colleague rshaffer61, that this may very well prove to be a corrupted MBR/ Boot Configuration data
After you have satisfied yourself that the drive is shown in the BIOS setup and it is listed as a boot device, please exit out of there it is normally F10 Save and exit
(If you require more advice on checking that in the BIOS please post)
Then please immediately after the screen where you see F1 or F2 try keying F8 by tapping the key repeatedly and see if you can get to a screen amongst which are a number of start options including Safe Mode and Repair Your computer.
Do not please progress beyond that apart from telling us the options on the screen.