You can connect it with a Reader to a computer and try this:
Start => Setting => Control Panel =>Administrative Tools => Computer Management =>Disk Management=> Right click your drive on the list => format it.
If there is any important data on your memory card, you have to recover it at first and then format it.
You should visit these articles to help you:How to Make a RAW Drive to Work Again Without Losing DataFree to recover photos and videos from formatted memory card
Memory Card RecoveryMemory Card Recovery After Delete or Format