WARNING: Your backup disk has developed bad clusters due to which some of your backed up data has been lost permanently. ...

WARNING: Your backup disk has developed bad clusters due to which some of your  backed up data has been lost permanently. This may be an indication of problems  with your hardware. Data for following volume(s) was not completely restored.  Please run CHKDSK /R on  volume(s) %1 to attempt to correct the errors.