1.
http://www.google.com or USB driver challenge inside your personal computer. Second, your card reader is broken. Try one more card reader. 3.
recover sd card partition table is broken. Find the particular grid card application grid card to try to repair. (The mobile phone can read the card, fundamentally excluded) Fourth, whether or not the memory card is set having a password, if it is cancelled, attempt the answer for the driver trouble: right-click 'My Computer' ---- Management ---- Appear in the Device Manager Do you may have a driver having a yellow question mark?