A: If there is data loss after drive became RAW file system and the data is precious, please recover the lost data firstly and then format the RAW drive to NTFS or FAT32 file system.
Read more How to recover data from RAW drive?
If the lost data is useless to you, format the RAW drive to NTFS or FAT32 file system directly and then the drive becomes accessible again.
Format the RAW drive with Windows built-in format tool (Open My Computer, click the RAW drive and select "Format" to format RAW drive to NTFS/FAT12/FAT16/FAT32 file system) or free partition manager and you will find the inaccessible drive becomes accessible again. If you think it necessary, you can copy all data back to where they before.