If there is data on the drive, do not format the drive! Formatting the drive will delete all of the data from the drive.

1. Open a command link prompt or Windows Power Shell.
2. Run the CHKDSK command. In the example screen shot the drive which is not accessible is the J drive. In this instance, we would run CHKDSK /f J:

When running the CHKDSK command, if error The type of file system is RAW CHKDSK is not available for RAW drives appears, this typically is an issue with Windows 7 or above. In this scenario, booting the computer using a Windows Operating System prior to Windows 7, or a Linux Operating System might be required in order to access the filesystem on the drive and recover the data.