Repairing boot processes using Knoppix

[Serioso]

I'm new to Knoppix and I'm hoping you can point me quickly at what I need.

I'm using the 5.1.1 CD to try to repair a newish system. I thought the problem was with the hard disc but Knoppix seems to show it OK. So it must be the BIOS or nvidia boot loader or (less likely) GRUB that's at fault.

I can't see anything in the FAQs about repairing BIOS or boot loaders or GRUB. Gparted and QtParted don't seem to address this at all.

Is there info anywhere about how to repair boot processes using Knoppix ?

I guess this is a silly question, and maybe the answer's staring me in the face, but I can't see it.

All the best, S

[Serioso]

I found out about testdisk which is surely what I need.

But:

Knopppix v5.1.1 CD won't allow testdisk to run. Using a terminal window as ordinary user, or with sudo, I get

/usr/sbin/testdisk Input/output error

I did the correction listed on the testdisk pages for 5.1, namely

ln -s /usr/lib/libnfts.so.10.0.0 /usr/lib/libnfts.so.9

(with sudo) but still get I/O errors when I try to run testdisk.

In other respects, Knoppix seems to be working fine.

Can you help? I'm mystified.

S