How do I Format my SD card?
It is recommended to format your microSD card occasionally if your camera records a lot of video. This is because of all the overwriting that occurs when the card gets full.  This can cause problem areas on the card.  This is similar to defragmenting the Hard Drive on your computer.
Go to Advanced Setting, SD Card Setting, Format SD Card.
This process will erase all video on the card and reformat the card.