You are really in a state of shock when the stored Mac hard drive file not responding. These files must be very important for you and you don't want to loose them. The reason why the files are not responding because may be they have been corrupted and can not be opened. The corruption can occur if the hard drive have bad sectors, the volume where the files are saved is corrupted like the file system is damaged, header file is damaged. If the drive is corrupted by the virus then also you can face the problem of stored Mac hard drive file not responding. To fix any hard drive problem you have to use the disk utility pre-installed in the Mac system which can scan for the problem and then try to fix it. If the issue is not solved then you have to format the drive which will also delete all the data and files. Now you can use any backup to restore the lost files and the time machine back up is the most useful in this situation. But sometimes the time machine does not work then you have to use the Mac data recovery software which can get back your corrupted and deleted files. So download the software now.