Hi, welcome to justanswer.com! My name is Mike.I am going over your question and will be with you shortly.
What do you mean by "can't open canonmsc"? Is this on the camera or the computer?
Did you try reformatting the card in the camera?
You have to format the card in the camera not on your computer.
So you can't read the card on your computer? Are you using a USB card reader or just plugging the camera in?
Are you using a USB card reader or just plugging the camera in?!! Yes formatting it loses everything.
I can remote connect and help you. Did you format this card in the camera before you used it?
Do you still want help with that?