I used a 64gb Sony Micro SD in my Handycam to shoot videos. When I try to download the video files to my hard drive in my PC, the error message appears, "Card cannot be formatted" and I can go no further. Took the Micro SD to a Sony Service Center, they said the card had a virus, said they re-formatted the card, said the card was okay to use. I can shoot video okay, but the error message appeared again, and now I'm afraid I'm going to lose some really nice birthday video files. If I spend more money on another Sony Micro SD card, should I format the card first before using?