This is your secondary drive right?(external probably)
It may have lost its partitions. You need to use some partition/data recovery tool in order to retrieve the data.
After that, it may be a good idea to check the drive's health out: http://www.tomshardware.co.uk/forum/282651-32-best-diagnostic-testing-utility
Look for pending/reallocated/uncorrectable sectors.
This is your secondary drive right?(external probably)
It may have lost its partitions. You need to use some partition/data recovery tool in order to retrieve the data.
After that, it may be a good idea to check the drive's health out: http://www.tomshardware.co.uk/forum/282651-32-best-diagnostic-testing-utility
Look for pending/reallocated/uncorrectable sectors.