How to Repair an Unreadable Hard Driveby Margaret Worthington
If you boot up your computer and one of the hard drives connected to it is suddenly unable to be read by the computer, you need to repair it before your computer can use it again. This problem can be caused by improperly disconnecting or powering down the drive while the computer is still using it. A quick scan of the drive with your computer's disk-checking and repair function can correct this issue.
Click "Start," then click "Computer."
Right-click the hard drive and click "Properties."
Open the "Tools" tab and then click on the "Check Now" button under the "Error-checking" section.
Check both options on the window that appears.
Click "Start." Once the program finishes running, you are alerted to that fact and can resume use of the drive.