Does your computer not recognize an external hard drive that on other PCs seems to work fine? Have you tried to connect it to various ports and also to change the USB cable but none of these solutions had the desired effects? There is obviously a configuration problem that prevents Windows from recognizing the drive correctly.
Perhaps you need to assign a new drive letter to the disk, or if the problem occurs on multiple computers, you may need to fix errors on the disk or initialize the device. Stuff from "geeks"? Absolutely not! Follow the directions on how to detect external hard drive that you find below and you should be able to solve the problem completely independently without calling your IT expert friend.
Assigning a disk letter and correcting the problems present in it does not lead to the deletion of data, while the initialization unfortunately involves the elimination of all the files on the drive: use this solution only when strictly necessary and only if the disc does not contain vital data. Otherwise you would do well to attempt a recovery of data from the disk through ad hoc solutions (we will talk about it in more detail in a while) and / or to contact the centers that deal with the recovery of data from damaged disks. Now, however, let's not lose ourselves further in chatter and let's get straight to the point, let's see how to detect external disks that make "whims".
Assign a Drive Letter
If you want to know how to detect external hard drive which seems to turn on regularly when you connect it to the PC but is not accessible from the computer resources, the first attempt you can do is access thedisk management utility included in Windows and try to assign a drive letter to the disk, which may have conflicted with other drives configured in the system.
To do this, access the disk management utility present in Windows by searching for the term partition on the menu Start and click on your voice Create and format hard drive partitions that appears in the search results.
In the window that opens, right-click on the icon relating to the external hard drive that is not recognized by Windows (eg. Disc 1 - WITHOUT TITLE and select the item Change drive letter and path give the menu to compare.
At this point, click on your button Change, select from the drop-down menu Assign this drive letter the drive letter you intend to assign to the external disk (ex. J:) and click on first OK and then Yes to save the changes. At this point, the disk should also be accessible from My Computer.
Do you use a Mac? In this case, instead of assigning a drive letter you may need to “mount” it in Disk Utility, the application included "standard" in macOS that allows you to manage all partitions and disks.
To start Disk Utility, open your Mac's Launchpad and click on the application icon in the folder Other. In the window that opens, select the drive name from the left sidebar (it should be the one located immediately under the name of the USB hard drive written in gray) and click on the button Attiva which is located at the top right.
The drive should now be active and then you should be able to access its contents via the Finder (or any other application installed on your Mac).
Initialize the Disk
If your PC fails to detect external hard drive just purchased, the device probably needs to be initialized: another very simple operation that can be performed by the disk management utility included with Windows.
To initialize a disk with the Windows disk management utility, right-click on the box relating to the external drive (where the writing Not allocated) and select the item New simple volume from the menu that appears. In the window that opens, click on forward for two consecutive times (make sure the simple volume dimensions are equal to the amount of space that was previously unallocated), choose the drive letter from the drop-down menu, set the name and file system to use for the volume (FAT/FAT32/NTFS, depending on your needs) and first click on forward and then OK e end to start formatting the external hard drive. Be careful, because this operation will delete any files saved on the disk!
If accessing the disk management utility automatically asks you to initialize the disk (A disk must be initialized to allow Logical Disk Management to access it), make sure there is a check mark next to the item MBR (Master Boot Record) in the window that opened and click on the button OK to initialize the drive.
Do you use a Mac? In this case, to initialize the hard disk that the computer does not recognize you must open the application Disk Utility located in the folder Other of the LaunchPad and you need to invoke the command Initialize which is located at the top right. To be more precise, you have to select the disk icon to format from the left sidebar and click on the button Initialize which is at the top right, after which you have to type the name to be assigned to the unit in the appropriate text field, you must choose the file system to use (eg. MS-DOS FAT o OS X extended) from the drop-down menu Format and you have to press the button Initialize but I will complete the operation.
If the Initialize button is not clickable, select the partition listed under the disk icon, activate it (if necessary) and format it following the procedure above.
What to Do if the Problem Persists
Despite my suggestions you still haven't been able to detect your external hard drive? I'm sorry, but don't throw in the towel just yet, maybe there is still some solution you can put into practice.
- Try to access the device management panel and uninstall the drivers related to the external disk. This will force Windows to re-download the drivers from the Internet, and who knows that this operation will not solve the problem. To go into more detail, what you need to do is click on the button Start, search for the term devices and click on the icon Device management that appears in the search results. In the window that opens, right-click on the external disk icon and select the item Uninstall from the menu that appears. Then reconnect the disk to your computer and wait for new drivers to be downloaded from the Internet.
- Make sure the external drive is formatted with a file system recognized by Windows. If your disk is not formatted with one of the most common file systems in Windows environment (FAT32, exFAT and NTFS) but with a different file system, such as Linux EXT3 / EXT4 or Mac HFS +, it could be this is the cause of the problem. To solve you should install drivers to read HFS + and EXT4 / EXT3 file systems on Windows as I explained to you in my guide on how to format HFS.
- Try to fix errors on the disk. If you can see the external drive in the Windows File Explorer but cannot access its contents, open the Command Prompt e dai il command chkdsk x: /f /r where instead of the "x" you must enter the drive letter of the disk. This will allow you to analyze the disk and fix any errors on it. If Windows fails to scan the drive, the drive is probably damaged and therefore it is advisable to use data recovery software.
- Use a data recovery software. If the situation seems desperate, before fully formatting the drive or taking it to a specialized center, try to recover the data on it using TestDisk or one of the other data recovery software that I recommended to you in my tutorial on how to recover deleted files.
- Check that the USB cable you are using is not broken and that the drive does not need external power to work (so that it does not need to be plugged in). I know, these are trivial advice, but often it is in these small things that one gets distracted and mistakes are made. It happens to everyone!