Having HD and boot device problems, please help!

[Siphon]

Just recently my computer has not been able to detect a boot device. I went into BIOS, it said it does not detect my HD or my CD-ROM. I tried booting off a cd, but it did not detect a CD-ROM. I restarted the computer and it was working once more. However, while I was using the computer it froze and I had to restart the computer again. When it started back up, it said it could not detect the boot device. So I restarted again and it redetected it, but after a couple minutes, my computer froze again. When I turned it back on, it could not detect a boot device. Since then, it has not been able to detect a boot device. I opened up my computer and I checked if the cables were firmly plugged in; they were. Now I have no idea where to go from here. What could have caused this problem? Could it be the mobo or the ribbon cables? Why did it detect it for a while, and then loose detection again? How come the CD-Drive as well lost connection? I have virus detection, but could a virus cause an error like this?

Please help me, I have some information on the HD that I would like to keep.

 

[Crashman]

It could be a bad cable, yes. Oh, and there's an odd chance it might be a weak BIOS battery.

<font color=blue>Only a place as big as the internet could be home to a hero as big as Crashman!</font color=blue>
<font color=red>Only a place as big as the internet could be home to an ego as large as Crashman's!</font color=red>