scan it with antivrus and anti malware software
if they cant cure it
u have to format the card
and on more thing before connecting your memory card via card reader,disable the auto run feature on your computer
If you want to remove a virus completely from a memory card and I'm assuming you mean a SD Card like this PNY Elite Performance XDSD http://www.amazon.com/PNY-Elite-Performance-Speed-Class... card. The best thing to do is reformat the card to remove everything from it. If a virus is still showing up then you have a virus somewhere else and not on the memory card.