Hi Ford,
If you go to top menu and go to Robot/NXT Brick/File Management, it will bring up a window to manage all the files on the NXT. I believe the upload button will let you take a file from the NXT to the PC.
FYI, the programs on the NXT are compiled and are no longer C files, they cannot be edited anymore or converted back into C files. So don't plan on recovering a program from the NXT, sadly it doesn't work

.
Scott B-)