There is nothing wrong with the Hard Drive.
You just have a serious scramble in the information on Track 0 of the Hard Drive.
Since you said the Emergency Disk etc. dosn't work, you are going to have to go one step more basic.
Find out the Manufacturer of the hard drive. (If you don't already know it.)
Go to the Manufacturer's Website, and download the Hard Disk Utility.
Make the floppy, and boot with it.
It will tell you what is really going on with Track 0.
(These Utilities also have other included programs that you may find useful, plus they are a FREE download.)
I hope you were able to backup the drive before you did this "reload".
From the wording of the question, I assume this was not the case.
You have just experienced the reason Tape or CDROM backups are still popular when important data is on the HD, or recover time is important.
Regards, Chris