In this article, I’ll try to go through the different solutions on Mac and Windows for fixing this issue. How the drive is formatted and what file system is being used is the most common reason why drive is not recognized.

Assign Drive Letter

If you’re having trouble installing or using a new driver, it’s possible that your computer isn’t recognizing the drive. To check, open Disk Management in Windows or Disk Utility on OS X and see if the drive shows up there. If it doesn’t, that might be the problem. ..

If you have an external hard drive that is not being recognized by Windows, you might need to assign a drive letter to it. Normally, Windows does this automatically, but sometimes because of other connected devices, your external hard drive will be recognized but not have a drive letter assigned to it. In Disk Management, just right-click on the disk and choose Change Drive Letter and Paths. ..

If your drive is not showing or you’re getting messages about the drive needing to be formatted, then read the next section below.

If the drive doesn’t appear in Disk Utility, you can check to see if it appears under the heading External in the Finder.

If the drive is showing here, but not on the OS X desktop, then click First Aid to try and repair the drive. If the drive has a file system not recognized by OS X, you may need to erase it and reformat it using FAT or HFS+. ..

If you’re having trouble getting your Mac to recognize the drive, there are a few things you can check. First, make sure the drive is properly connected to your Mac. Second, make sure the drive is formatted with the correct type of file system. Finally, make sure the drive is properly initialized. If you’re having trouble getting your Mac to recognize a disk or partition, there are a few things you can check:

  • Make sure the disk or partition is properly connected to your Mac - Check that it’s formatted with the correct type of file system - Make sure it’s initialized ..

Format Drive

When it comes to file formats, there are a couple of major formats that are used about 99% of the time: FAT32 and NTFS for Windows and HFS+ (Mac OS Extended) for Macs. Now OS X can read and write to FAT32 formatted drives, but can only read NTFS volumes.

Windows is worse in the sense that it cannot even read or write to HFS+ formatted volumes by default. You can get Windows to do it, but you have to purchase third-party software. The only other option is to format the hard drive and use the FAT32 format for the best compatibility. ..

When you connect a HFS+ formatted drive to Windows, you’ll get a message stating that the drive needs to be formatted in order to be used.

If you see this message, it means that Windows does not recognize the drive as a drive and cannot format it. Make sure you connect the drive to the appropriate operating system and backup any data that you might need before performing a format.

There are newer, more compatible formats such as exFAT, but they require a new drive and are not backward compatible with older operating systems. So what’s the best format to use so that you can see your hard drive on multiple operating systems? The answer is that it depends on your needs. If you only plan on using your hard drive with one operating system, then the legacy FAT32 format is the best option. However, if you want to be able to use your hard drive with multiple operating systems, then it’s best to use one of the newer formats such as exFAT. ..

If you need support for larger files, then you should use the exFAT format. It’s newer and supports much larger files, but only works with newer versions of OS X and Windows. You’ll have to be running OS X Snow Leopard (10.6) or higher or Windows XP or higher.

In Windows, you can choose exFAT as the file system format in addition to NTFS and FAT32. When you format a drive in OS X using Disk Utility, you can also choose the exFAT format if you like.

Drive Not Showing Up

If you connect the drive to the computer and nothing happens, one of several things could be going on: your hard drive might have a problem, the correct software or drivers are not installed on your system, or there is something not working properly with the operating system. Let’s start with some common problems and their solutions.

Windows – Device Manager

netstat -an | grep “inet” If the command returns a list of active TCP/IP connections, then you can try connecting to one of these connections and seeing if it works. If not, then you may need to fix the device by going to the manufacturer’s website and purchasing a new one.

Now, under the “Devices” heading, you’ll see a list of all the devices that are currently hidden. Click on any of them to show their properties.

Right-click on any items that are grayed out and choose Uninstall. Restart your computer and try to connect the hard drive again.

If you are having trouble locating a Portable Device or Disk Drive on your computer, you can try expanding out the storage space on your computer by installing a new Disk Drive. If the Portable Device or Disk Drive is not showing up properly in Windows Explorer, you can try uninstalling it from there. ..

Windows – USB Device

If you get a USB Device Not Recognized error when trying to connect your USB drive to Windows, make sure to check out the link on how to fix that problem. Windows tries to blame the device for malfunctioning, but it’s usually a problem with Windows. ..

USB Ports/Secondary PC

If you are connecting the drive to a USB port on the computer, make sure it is not a problem with that particular port. If you are connecting to a USB hub, disconnect that and try to connect the drive directly to the computer. ..

If the computer or hard drive doesn’t work, it’s most likely because something is wrong with the drive.

Drive Tools

If it appears that the drive is not working properly, you can try to troubleshoot the drive by using the diagnostic tools from the drive manufacturer. Just about all the major brands like Seagate, Western Digital, Toshiba, etc., have these diagnostic tools.

If you have a hard drive that is not working properly, you can use these tools to check it for errors and fix them.

USB 3.0 Drives

Secondly, make sure your computer is able to see the drive. If your computer doesn’t support USB 3.0, you may have to use a different type of cable to connect the drive to your computer.

In order to update the driver for your USB 3.0 device, you will need to go to Device Manager and expand Universal Serial Bus controllers. Right-click on the one that has USB 3.0 in the text and choose Update Driver.

Power Issues

If your hard drive is not powering on, there are a few things you can do to troubleshoot the issue. First, make sure that the hard drive has the correct external power adapter and that the light on the front of the drive is turning on and is not orange or red. Next, try using different cables as some are able to carry more power than others. If these steps do not resolve the issue, then your hard drive may have failed and you will need to replace it. ..

If you have an external hard drive that doesn’t show up in Windows or Mac, here are some tips to help get it recognized.