my memory card has a picture in it bt it shows empty
Are you trying to save the picture(s) that's on the card, or just make the card usable and remove the virus?
If you don't care about the picture, format the card in the camera. (Your camera should have an option to format the card). All pictures will be lost, but the card will be clean of viruses.
hey , you can get the picture back without any software,
after you copy your picture, you can format the usb.
go to CMD
type in : attrib -h -r -s /s /d x:\*.* (x is the letter drive of your usb)