How to access an unmountable hard drive on Mac Mountain Lion? Is this the issue, which you are searching for? Then, have patience and be relaxed. Although, Mac mountain Lion is a well developed, highly rated operating system. But sometimes it shows some unwanted result causing data inaccessibility. Unmountable hard drive is one among them, which Mac users often face after partitioning their Mac hard drive. Now, a question arises how to access an unmountable hard drive on Mac Mountain Lion? Further, the unmountable issue also arises due to malware attack, generation of bad sector into the hard drive, OS corruption and also due to improper file formatting. As a result, Mac system fails to mount the Mac hard drive and the volume become useless. Now, to rescue the problem and to get rid of how to access an unmountable hard drive on Mac Mountain Lion issue, users should may go for restarting their PC severally. But, the problem still exists. So, in such situation re-formatting or re-partitioning is the only option to overcome unmountable hard drive issue. But, doing so will erase all the stored data files. So, to recover lost data files, an effective Mac data recovery software come to your help.