SD card help

So I forget to bring my SD card to Oshkosh. SWMBO has a 4GB card, loans it to me, and everything seems fine. Started getting an error message on my Nikon D-3000. Her Nikon Cool Pix stores pics as Jpegs, while mine stores them as RAW and Jpeg. Could this be the culprit? I tried the CHKDSK command in command prompt, but it said that it cant fix RAW files. The card reader in the HP desktop recognizes that there's something in the slot, but will not read it, and seem to lock up My Computer.

Did I do something wrong? Before I download some sketchy software to try to recover these pictures, any input? Recommendations?

The different file formats aren't related to the problem. I'd recommend you get a binary image of the card first of all so you can make further attempts at recovery even if the physical medium fails. I hope you're not afraid to try Linux because most of the good data recovery tools are on that OS. So you might as well make yourself a Mint or Ubuntu liveCD/liveUSB right away.

First I'd use ddrescue to make a binary image, and then I'd use photorec (photo-specific file recovery program) to try to recover the picture files.

If this fails the only remaining option is to send it to a professional data recovery shop where they can try to decap the SD card to read data directly from the flash storage ICs inside.

Linux is a bit out of my league at the moment. Any you could recommend running Win7pro? Any idea what the pros charge for this? And recommended outfits?

Photorec is available for Windows. This program can take a binary image of a drive but doesn't have the advanced automatic error handling of ddrescue:

http://hddguru.com/software/HDD-Raw-Copy-Tool/

Pros will charge anything from a couple hundred to mid-4-digits depending on what kind of work is needed. Kroll OnTrack is the go-to data recovery megacorp.

First up, check the file lock switch on the side of the SD card. I had a card that the computer would not let me play with at all. It would not allow me to format it either...

The file lock switch just prevents you from writing to the card. Best-case scenario, it could be preventing you from doing a simple filesystem repair, but Windows' filesystem repair utility is so hamfisted that it could easily make things worse if there is a more serious problem.

I know what it should do, but in my case it was loose, and somehow completely disabled the card's functionality until firmly pushed home. Twas just a suggestion.

I know you say Linux is out of your realm, but I've had much more success with photorec than any windows tool. If it is that important, you can follow a guide to boot a live distro and run the tool. I believe it is included in the current ubuntu live CD.

Some cards just die too :-(

Looks like the reader might be reading it. It states that the card must be formatted. Not doing that, because I'd want my pictures, but at least it doing something..

Use HDD Raw Copy to get an image as soon as you can. If it repeatedly fails with errors, you'll have to use ddrescue on a Linux liveCD to do it.