Does that mean the HD needs to be replaced?

I was able to install the hard drive as a slave in another computer, and was able to copy my documents onto the primary.  I then formated the drive.

 

Thanks again

A code 79 means the hard drive has failed, usually to bad sectors. 

Yes, it means that it needs to be replaced. 

 

Although you were able to slave the hard drive and recover files, the bad sector the diagnostics is referring to maybe the boot sector of the drive.  That would prevent the hard drive from booting up an operating system.   Once the drive starts to produce bad sectors, you can almost guarantee that more will follow until the drive is unusable even as a slave.