External hard disk raw error need to be formatted

Disk is not formatted; do you want to format it now? Or you have to format the disk in drive O before you can use it. Do you want to format it now? Those are two similar prompt above which means the external hard disk raw error when can not use it normally. In this situation, the file system of the external hard drive will show RAW. It seems that there is no way but to format it if we want to use that drive again. It is right, to a certain extent. But there is another thing need our attention. How to access data saved on that unformatted external hard disk? No matter we format it or not format the raw external hard disk, it seems that we can not view data saved on it previously. Fortunately, we can retrieve data form the raw external hard disk.