By Emily / Last Updated April 22, 2020

”What do I do if my second hard drive not detected in Windows 10?”

“For some reason my secondary hard drive keeps disappearing randomly while Windows 10 is running. The drive stays until some random moment when Windows cannot detect it any more. With a simple restart, the drive cannot be detected and won’t show up, only after I shut down the machine completely, and push the power button back on, does this work. Why is my second hard drive not detected and showing up in Windows 10? What should I do to fix it?”

Most Windows 10 users probably tend to use two hard drives (internal main hard drive and another external hard drive) for data storage requirements. However, some of them might meet the "second hard drive not detected in Windows 10" issue now and then, especially after a Windows 10 update. So, in this article, we will share the causes and solutions to external hard drive not detected problem.

Why second hard drive not showing up in Windows 10/8/7?

What on earth leads to second hard drive not detected in Windows 10/8/7? Well, below are some major reasons you can take a look at:

Connection issues: the hard drive is not connected properly. Or the power supply, cable or USB port, etc might go wrong.

Hard drive is not initialized: disk is marked as "Unknown, Not initialized" in Disk Management, so you cannot see it in File Explorer, either.

Hard drive not being partitioned: the hard disk has no partition and all disk space is unallocated, it won't show up in Windows Explorer.

Hard disk partition without a drive letter: if a partition of the hard disk does not have a drive letter, then you cannot find in Windows Explorer.

Outdated disk driver: when the driver of the hard disk is outdated, it won’t be detected by your computer or system.

Bad sectors on the disk: when there are any bad sectors on the disk, the Windows system might be unable to recognize it.

What to do when the second hard drive not detected in Windows 10?

The second disk sometimes cannot be found in File Explorer but you can get it in Disk Management? Or you cannot see it in both of them? Different situations need different solutions, and here we will show you what to do in different cases.

Try the easiest things first:
Verify whether the hard drive cables are connected correctly and the two cables work well. That’s because if the connection cables get loose, there is a possibility that the disk does not show up in Windows.
Make sure the SATA port, USB port, and power supply work fine, too.
If everything is right, but the problem is still there, try one of the following technical solutions.

Case A. Second hard drive not showing up in File Explorer

If you cannot find the second hard drive in File Explorer, but you are able to see it in Disk Management, the following solutions might help.

Solution 1. Initialize and partition the second hard drive

When the hard drive is not initialized, you won’t be able to see and read it in Windows File Explorer.

1. Right-click "This PC/ My Computer">"Manage"> "Disk Management" to open Disk Management

2. Find the hard drive and right click it, select “Initialize Disk” from the given menu, then follow the hints to initialize the disk into MBR or GPT.

Besides you can also use PowerShell to initialize disk. After you initialize the disk, the disk will be shown as unallocated space, then you need to partition it to make the drive visible in Windows.

3. Right click on the unallocated disk space and select "New Simple Volume". And click “Next” on the welcome page.

4. Fill in the “simple volume size” to the desired value in Megabytes, then click “Next”. Notice the minimum and maximum allowed size when creating the partition.

5. Choose “Assign the following drive letter” and select the desired drive letter from the dropdown menu. Click “Next” to continue.

6. On the Format Partition page, you can decide the file system, allocate unit size and volume label. After everything is done, click "Next", and then “Finish” to proceed.

To create more than one partition on the second hard drive, you can leave some free space in step 4. And repeat the steps to create another partition. If you want to quickly partition a large hard drive into several partitions at one time, you can use AOMEI Partition Assistant Professional instead.

1. Install and launch AOMEI Partition Assistant Pro from your computer. Right-click the second hard drive and select "Quick Partition".

2. In the pop-out windows, you can set the disk type, partition counts, partition size, and volume name, file system and so on. After all are done, click "Start Partitioning".

Quick Partition

With two clicks, you can create multiple partitions at one time instead of creating them one by one.

Solution 2. Assign a drive letter

Lack of drive letter, the second hard drive won’t show up on This PC/My Computer, either. So try changing the drive letter following the below steps.

1. In Disk Management, right click the second hard drive and select "Change drive letter and path".

2. Choose a letter for your partition from the list and confirm.

Assign Drive Letter

3. Then restart your computer.

Note: if the Change Drive Letter and Paths Greyed Out in Windows 10/8/7, you can turn to AOMEI Partition Assistant Pro, too.

Case B. Second hard drive not showing up in Disk Management

If you cannot even find the second hard drive in Disk Management, then other different solutions are required.

Solution 1. Update the driver

If the second hard disk driver is outdated, then it won’t appear in Disk Management and File Explore. In this case, you need to update the driver in Device Manager:

1. Right-click on Start, click "Device Manager".

2. Expand Disk driver and locate the hard drive which cannot be detected by Windows.

3. Right-click on the disk and select "Update Driver Software" from context menu.

Update Driver

4. If there are any updates, follow further instructions to update the disk driver.

Solution 2. Uninstall and reconnect the second hard drive

In addition to updating the disk driver, you can try to uninstall and reconnect the external hard drive to get Windows 10 detect it.

1. Enter the Device Manager interface as solution 1.

2. Double click Disk Driver to expand it.

3. Right click on the second hard drive and select “Uninstall”.

Uninstall Disk Driver

4. Reboot your computer after uninstalling this disk is finished and plug in the hard drive again.

Solution 3. Check and fix bad sectors on the second disk

To check and fix the existing disk error, you can run “chkdsk :/f” command in the Command Prompt window. Here is an example to check and fix errors on G: drive.

1. Press Win+R at the same time, type “cmd” in the Run dialogue and press Enter to get Command Prompt window open.

2. Then input “chkdsk g: /f” in the window and press Enter to execute it.

CHKDSK Disk Error

But if you are not familiar with such complicated commands, you can switch to the AOMEI Partition Assistant Professional. It could also make checking and fixing errors a simple task.

1. Run the software, right-click the second hard disk and click "Advanced"-> "Check Partition".

Check Partition

2. Select the first way to check as well as fix the disk error, and click OK.

Check And Fix

3. Then wait for the process to finish.

Case C. Second hard disk not showing up in BIOS

When you find your hard drive is not showing up in BIOS, try the following steps to troubleshoot the problem.

1. Restart your computer and keep pressing F2 (or F1, Delete) to enter BIOS;

2. Enter Setup and check system documentation to see whether the second hard drive is turned Off in System Setup or not;

3. If it's Off, turn it ON in System Setup.

4. Reboot PC to check if it can be recognized in Disk Management.

Case D. Second hard drive not detected after Windows 10 update

If the second hard drive is not detected by Windows 10 after a recent Windows 10 update, there are chances that a “broken” Windows version has been somehow installed on your computer system, then you can choose all new updates.
1. Select Start and then choose the “Settings” icon on the Windows 10 desktop.
2. Choose “Update & Security”. And locate “Windows Update” can check if there are any pending items. If there are, install updates.
At last, check if the external hard drive is still not detected by Windows 10.

Conclusion

So many effective methods introduced elaborately, it won’t be challenging to deal with “the second hard drive not detected in Windows 10/8/8.1/7” issue. More importantly, AOMEI Partition Assistant can also help solve other similar disk issues like BIOS detect hard drive but Windows does not, USB flash drive showing 0 bytes or no media, cannot format 0 bytes USB, etc.

To deal with similar issues in Windows Server 2019/2016/2012/2008/2003,etc, you can make use of AOMEI Partition Assistant Server.