Go to the web site of the hard drive manufacturer, they usually have disk scanning utilities. Worth a shot.

The split-in-half photos happen in the camera, I just learned that in a camera class and had one out of 500 pics turn out that way recently. Might be the camera if you never really examined a lot of the photos on a computer monitor.

If they aren't real bad, use Adobe Photoshop Lightroom, it can correct a lot of the problems with digital camera shots. When there are things like walls with scratches on them in the background, etc; I just turn clarity down and it smooths things out. I don't know if recovery will help, but turn that up to see if it can fix anything, probably not.

Try going into Linux and viewing the files, search for some Linux boot disk utilities for diagnosing the problem. There are some really good ones.

I hope as others have mentioned that you aren't stuck with photos you can no longer use.

You probably have much better storage now, but as a tip for the future, always send your pics to an online account. I send mine to Windows Live Skydrive because you can just drag and drop and it's free.