What can I do when chkdsk says "the volume appears to contain one or more unrecoverable problems"?

"I had a similar problem on a computer once (the drive was still recognized, but Windows hung reading it).

I used a Linux resuce CD (any distro will do) and ddrescue (part of most distros) to boot the sick system, and copy the whole partition to a fresh external drive (via USB). ddrescue is very nice for copying partly defective media: It will automatically skip defective parts of the drive when reading, then try to read them once everything without errors is copied.

You could try booting from a Linux rescue CD to see whether it still sees partitions. If it does, you might be able to rescue them as in my case. Once you have a copy, you can try to recover from it without fear of damaging the original.

If you cannot even see partitions, then the other answers might help. Or, if the data is important, consider a professional data salvaging company."