With a breakthrough capacity of 400 GB, you can store even more hours of Full HD video on the card without worrying about running out of space. If microSDHC cards fail to format, it may be possible to read and format the card using a USB memory card reader. In theses cases, you can use a reader to download your data or recover it using a data recovery program like Rescue Pro. After you backed up your data, you can simply format your card and continue using it in your device.