I've re-read your message a few times. What I think it's saying is that
your jpeg files are still there on the card but you've lost the association
to them in Windows. In this case all you have to do is use the Open With
dialogue and find your usual photo-editing or image viewing program to view
it with, making sure that the box is ticked next to 'always use this program
to open this file in future'.
For reference, on Windows ME try c:\windows\kodakimg.exe