Everyone does this once, some twice! I'm included. I use Lexar cards and they have software downloads just for this job and I would expect the same of SanDisk. MOST IMPORTANTLY, don't do anything else with the card until you run the software, which may take some time. Check the packaging, or the SanDisk site for more information. Nothing will be lost except some time. Best of luck.
Well, I can't check the packaging, since it is long gone. Thanks for wishing me luck.