Sector 0 is the only one that cannot be remapped, I't a paper weight. However, even with a bad sector 0, you should be able to see the data on the drive unless the defect grew beyond sector 0 and corrupted the MFT.
I suggest putting the drive in a second PC or an external enclosure and see if you can see the data. If not, run a chkdsk /r on the drive, or Spinrite if you have it. At this point, how important is getting to the data on the drive? I am optimistic a chkdsk will get you to a point where you can at least see and recover your critical data.