Hello,
If the drive says Unallocated in disk management it means the partition is either corrupted or was deleted. You will have to format this drive in order to use it again. Formatting the drive will delete all data stored on it. However, it may be possible to still extract the data utilizing data recovery software. Western Digital does not provide data recovery software. However, there are several kinds of Data Recovery software available. If you do a web search for “Data Recovery” it will yield plenty of data recovery software options.
