Why the Disk you Inserted was not Readable by this Computer?

In a Mac OS based system, a user will encounter various types of errors and problems while using an external drive with it. And the disk you inserted was not readable by this computer error message is one of them. Usually, this error appears on the MacOS based systems due to some software issues related to the drive and the system. However, in a few situations, this error is caused by some hardware problems of the external drive. Now, if you are one of those users who is facing this same error while using an external drive, then follow this article to know about the possible solutions.

Major Causes of “The Disk You Inserted Was Not Readable By This Computer” Error Message

In this section, we have provided some examples of those problematic factors which causes this error in the user’s system. Have a look at them:

  1. Faulty external drive
  2. The drive is not formatted properly
  3. File corruption issue.

Now, if you have analyzed all the possible causes of the disk you inserted was not readable by this computer error message then let’s have a look at the solutions.

Solutions for “The Disk You Inserted Was Not Readable By This Computer” Error Message

There are various types of solutions that you can use in order to remove this error from your Mac-based system. But, you need to apply them in the correct order to get an effective result. Now, to help you out in that task, we have provided those solutions in the area below. Have a look at them and try to execute them as instructed:

Check the Drive

Most of the time, this error message is triggered by a faulty external drive and it is quite possible that your Mac OS based system is detecting this same problem. That’s why you should eliminate the possibility of this problem first. To do that, disconnect the problematic drive from your system and plug a new one. If the new external drive is showing the same error message then it means that the real cause of this issue lies in your system. However, if the new drive is working perfectly, then it clearly indicates that your old drive is faulty and you need to replace it with a new in order to fix this error message.

Repair the External Drive

Next thing that can create the disk you inserted was not readable by this computer error message on your system is the issue related to the files being corrupted. Sometimes, a few sections of the drive get corrupted due to erroneous files or applications and later on those things cause this error on user’s systems. Now, to repair those corrupted sections and files the user needs to run the Disk utility on their MacOS based system and if you want to do the same thing then follow the given steps:

  1. First, when the initial prompt appears on the screen, click on the  Ignore option in order to dismiss it.
  2. Then, you need to click on the Launchpad and type “disk” on it. Once you do that, the  Disk Utility will come upon the result area. Click on it.
  3. In the Disk Utility, you need to select that disk option which is marked with the error sign and then hit on the First Aid button.
  4. Now, the drive repairing procedure will start on your system. It will take some time, so be patient. After the procedure is completed, a confirmation message will appear on the screen saying that the procedure was successful.

Once, you get that message, restart your system and check if the external disk becomes available for use or not.

Set the Correct Format

Another most common issue that can cause this error in your Mac-based system is an improperly formatted external drive. A lot of users have been encountered this particular error message on their system because the external drive that they are using is formatted with the NTFS format. And the MacOS X is not compatible with that type of drive format. Now, if you are facing the same format issue on your system then follow the given instruction in order to resolve this problem:

  1. First, dismiss the error message and open the Disk Utility on your system.
  2. In the Disk Utility, you need to select that drive option which is showing the error message. Then, click on the Partition option.
  3. After that, select the number of partitions by using the Partition drop-down menu and then click on the Format option. A new menu will appear on the screen. There you need to click on the MS-DOS (FAT) option.
  4. Then, you have to confirm the process by clicking on the Apply option. And to initiate the process click on the Partition option.

Now, you need to wait until the process gets finished. Once it is, check whether your external drive has become visible or not.


We hope all the solutions mentioned in the above section are able to help you with the disk you inserted was not readable by this computer error message situation. For more tech-related information, keep following our upcoming posts.

Nathaniel Villa
Nathaniel Villa