The hard drive is on it's way out, there is no 2 ways about it. Chkdisk wont find the bad sectors once they have been labeled bad as they are ignored and not used after that. If you cant afford to loose data, then you should have backed up that data. At some point soon, that hard drive is going to either corrupt further or pack up altogether. Once data is damaged it's damaged, It's as simple as that. Recovery software can only do so much. It seems the damage is already too bad for the software. I take it you have never experienced a hdd failieure before, i have seen many. You are extremely lucky that you can access any data at all.