If after reinstalling Windows 7 or 8.1, and also after updating them to Windows 10, your computer does not see the second hard drive or the second logical partition on the drive (drive D, conditionally), in this manual you will find two simple solutions to the problem, as well as a guide to eliminate it. Also, the described methods should help if you installed a second hard drive or SSD, it is visible in the BiOS (UEFI), but not visible in Windows Explorer.
If the second hard drive does not appear in the BiOS, but it happened after some action inside the computer or just after installing the second hard drive, I recommend that you check first if everything is connected correctly: How to connect the hard drive to the computer or a laptop.
How to “enable” a second hard drive or SSD in Windows
All we need to fix a problem with a disk that is not visible is the built-in Disk Management utility, which is present in Windows 7, 8.1, and Windows 10.
To start it, press the Windows R keys on the keyboard (where Windows is the key with the corresponding logo), and in the “Run” window that appears, type diskmgmt.Msc then press Enter.
After a short initialization, the disk management window will open. In it, you should pay attention to the following things at the bottom of the window: are there any disks in the information about which the following information is present.
- “No data. Not initialized ”(if you do not see a physical HDD or SSD).
- Are there areas on the hard drive in which it says “Not allocated” (if you do not see the partition on the same physical drive).
- If there is neither one nor the other, and instead you see a RAW partition (on a physical disk or logical partition), as well as an NTFS or FAT32 partition, which does not appear in the explorer and does not have a drive letter, just right-click on it under such a section and select either “Format” (for RAW) or “Assign a drive letter” (for an already formatted partition). If there was data on the disk, see How to recover a RAW disk.
In the first case, right-click on the name of the disk and select the menu item “Initialize Disk”. In the window that appears after this, you must select the partition structure. GPT (GUID) or MBR (in Windows 7 this choice may not appear).
I recommend using MBR for Windows 7 and GPT for Windows 8.1 and Windows 10 (provided that they are installed on a modern computer). If not sure, choose an MBR.
Upon completion of the initialization of the disk, you will get the “Not distributed” area on it. I.E. The second of the two cases described above.
The next step for the first case and the only one for the second is to right-click on the unallocated area, select the menu item “Create a simple volume”.
After that, it remains only to follow the instructions of the Volume Creation Wizard: assign a letter, select a file system (if in doubt, NTFS) and size.
As for the size. By default, a new disk or partition will occupy all the free space. If you need to create several partitions on one disk, specify the size manually (less than the available free space), then do the same with the remaining unallocated space.
Upon completion of all these steps, a second disk will appear in Windows Explorer and will be suitable for use.
Below is a small guide, where all the steps that allow you to add a second disk to the system (turn it on in Windows Explorer) described above are shown clearly and with some additional explanations.
Making the second disk visible using the command line
Attention: the following way to fix the situation with the missing second disk using the command line is given for informational purposes only. If the above methods did not help you, but you do not understand the essence of the commands below, it is better not to use them.
I also note that these steps are unchanged applicable for basic (non-dynamic or RAID disks) without extended partitions.
Run the command line as administrator, and then enter the following commands in order:
Remember the number of the disk that is not visible, or the number of that disk (hereinafter referred to as N), the partition on which is not displayed in Explorer. Enter command select disk N and press Enter.
In the first case, when the second physical disk is not visible, use the following commands (note: the data will be deleted. If the disk is no longer displayed, but there was data on it, do not do the described, maybe just assign a drive letter or use programs to recover lost partitions ):
- Clean (cleans the disk. Data will be lost.)
- Create partition primary (here you can also set the parameter size = S, setting the size of the partition in megabytes, if you want to make several partitions).
- Format fs = ntfs quick
- Assign letter = D (assign the letter D).
In the second case (there is an unallocated area on one hard drive that is not visible in the explorer) we use all the same commands, except for clean (cleaning the disk), as a result, the operation to create the partition will be performed on the unallocated location of the selected physical disk.
Note: in the methods using the command line, I described only two basic, most likely options, but others are possible, so do this only if you understand and are confident in your actions, and also take care of the safety of the data. You can read more about working with partitions using Diskpart on the official Microsoft page Creating a Partition or Logical Disk.