format the HDD. since it is a slave i assume no partitions in it. It will be a single drive in My computer.
goto command prompt. go to the slave hdd's drive. and type
 chkdsk /x
If it asks for confirmation give 'y'. IF this doesn't solve ur problem u need to run any other program such as Tune up's disk doctor. or any defragmanter like Perfect disk , diskeeper.