2007 is too old to read a modern filesystem like ext4.
thats what i thought.
anyway. i have the new OS up and running (off a USB). i typed in 'fdisk -l' like you said, and it returned saying 'unable to seek on /dev/sda' im going to assume this is an issue?
Turn off the machine, unplug the main power cord, then remove the side and unplug and replug the data cable leading to the hard drive, at both the drive and the motherboard ends. Also unplug and replug the power connector at the drive. While you are in there, pop the RAM cards out, then replace each, making sure each is firmly seated and the end clips lock in place. Replace the side, reconnect the main power cable, reboot the machine, and try again.
If you get the same results, odds are your hard drive has failed.