"I look in my bios and it seems that it is no longer recognising my hard drive any more. I haven't touched my hard drive and when I check the connections are fine. I put it higher in priority and still nothing."
which seems to contradict, how could you put it higher in priority if it is no longer recognised?
Can you explain further on that point?
You need to have it recognised in the bios as it is the bios that tells pc what to boot into.
In order to test that the harddrive is not dead, is there anyway you can take the harddrive out and hook it up as a (slave) secondary drive in another pc to see if you can read its contents, which will then prove that the harddrive is okay and not dead.