So my Mac recently froze and after not being able to even get force quit up, I just held down the power button. After trying to restart it several times, I only got the apple logo and spinning wheel with a grey loading bar. I'm guessing hard drive failure. Ran single user mode with sbin/fsck -fy and it came back with Invalid Node Structure and disk0s2 (hfs) exited with signal 8. Is there any way to repair the hard disk without the original CD or replacing the hard drive? I have another laptop, FireWire cable, and Ethernet cable. Any program, regardless of the cost. Help??