Connecting your USB flash drive or external hard drive to your computer only to be met with a “device not recognised” message can be worrying and frustrating.
If your USB device isn’t being recognised by your computer, try not to panic; the chances are it’s nothing that can’t be fixed. The first thing you should do is to try another port on your machine, in case the port you’ve tried is damaged. If it isn’t recognised in another port, try connecting it to another machine. If it still isn’t recognised, you’ve narrowed it down to a problem with your USB device rather than your machine.
Your next course of action should be to check if your device is showing up in Disk Management. To access this, hold Windows+R, type ‘diskmgmt.msc’, and press enter. Once launched, you should be able to see a list of devices that are connected to your machine – for example, the hard drive or solid-state drive that is acting as the primary drive will be the C: drive. Your USB flash drive should be called F:, but otherwise you should be able to locate it by looking at the capacities. If you can see your USB flash drive in Disk Management but can’t access it, this could be because of a damaged partition. You can repair a damaged partition table using free data recovery software like TestDisk. There could also be an issue with the drive letter assigned to your device. To fix this, right-click on your device and select ‘Change Drive Letter’, making sure you assign a unique number that isn’t currently in use.
Another possibility is a driver issue. To check, launch Device Manager by holding Windows+R, then typing ‘devmgmt.msc’, and pressing enter. A driver fault is indicated by a black and yellow exclamation mark next to your USB device. You can reinstall the driver, or alternatively, roll back to a previously-installed driver.
Unfortunately, if your attempts so far have failed, it’s possible that your USB device has suffered from a hardware fault. USB flash drives in particular are often made with cheap components, and are prone to breaking. External hard disk drives are similarly very easy to damage. If the data on your device is important, you should consult a professional data recovery specialist.
