My hard drive can't be accessed but is recognised by BIOS

If your hard drive is spinning without a problem but is not recognised by your computer's BIOs this an be a sign of logical failure. This type of failure can be the result of defective media or data corruption from another source. In this case, first check the jumpers, which will vary according to the configuration of the hard drive. You should also check that the connectors and power supply are properly connected. In severe cases, there may be a problem with the circuit board. In the majority of logical failures, you should be able to recover the data via a data recovery software.

My hard drive is not being detected by Windows

One of the most common questions we hear is, "Microsoft Windows on my PC is not recognising my hard drive. What should I do?". Firstly, you should restart your computer, check the connections and plug your external hard drive into another PC. If the problem persists, there could be two reasons: - The disk is still not recognised by Windows – If you have checked the connections and plugged your hard drive into another PC, but it is still not recognised, the hard drive could be defective. - The hard drive does not appear in Windows Explorer 10, 7 or 8 but is detected by the computer – there could be a letter assignment problem in Disk Management – the hard drive doesn't have a letter by its name, so Windows File Explorer won't be able to detect the disk partition.

My hard drive is not being detected on my Mac

In this case, you should first check whether your external hard drive is recognised by another system. If you have access to a Windows or Linux PC, plug your external hard drive in; if it is recognised, perform a repair from the terminal, you can do this with the commands' diskutil list' and 'diskutil info disk'. Improper removal of the device can cause damage, so ensure you safely remove the drive before unplugging the external hard drive. If the external hard drive is not recognised when you plug it back into the Mac, first ensure your USB cable enables the USB port's auto-power function. If the hard drive is still not recognised, verify that the 'Finder' settings allow you to view newly connected devices. If your hard drive is NTFS formatted, non-native to the Mac, the Read Utility may need to be reset (Paragon NTFS us available in most versions of the Mac OS). If the external hard drive continues not to be readable and is not visible on the BIOS of other systems (Windows or Linux), then a hardware failure should be considered.

How to access an unrecognised hard drive?

It may seem simple but change the USB port and check that your USB cable is functioning properly. If the hard drive is appearing in the utility but is not accessible, you will need to repair it using the terminal commands. If the hard drive continues not to be recognised, you may have to use a data recovery software to locate the files.

Should I format my hard drive?

You should only format your drive if you have no data (or data you do not need) residing on it. You will need to choose the right format that suits your computer. Opt for NTFS or FAT32 if you are on Windows, and HFS +, ExFat or Mac OS Extended if on Mac. Remember that formatting a hard drive will erase all the stored data, so only choose this method if your hard drive is empty.

(External) Hard Drive Not Detected or not Recognised?

Q: My hard drive is not recognised and appears dead

A burnt circuit board (PCB) is one of the most common problems seen in hard drives. A power surge, overheating or an inadequate power supply can result in a hard drive frying its spindle driver chip leaving the data inaccessible. In some older models, you may be able to swap the PCB from another model. But most modern hard drives have logic boards that have been adapted to the head disk it was manufactured with. In those cases, a data recovery specialist will need to rebuild the parameters or transfer them from the fried board to the donor PCB to make it fully compatible with the damaged hard drive.

Q: Why is my external hard drive not recognised by my MAC?

It could be as simple as the USB cable being worn out or that the utility of the Mac is misconfigured and is not displaying any connected devices. If the hard drive is not partitioned in HFS+ format, the Mac OS X format, or ExFat format, verify that your utility is correctly installed. If you have checked all of the above, there could be a hardware problem. In this case, you will need to contact a data recovery specialist.

Q: Is updating drivers a solution?

When your hard drive is detected by your computer but is not displayed in Windows Explorer, you can try to update the driver. To do this, you should follow these instructions: 1/ Open the "Device Manager", 2/ Right-click on the start button then click on "device manager". In this list, a coloured indicator may appear to indicate any errors, 3/ In the "Disk drive" section, you will find the reference of your disk. Right-click on it then click on "Update Driver". The update will automatically be taken over by Windows Update.

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Sometimes our storage devices, hard drives, memory cards or other USB sticks are not recognised by the operating system, making it impossible to access our professional or personal data. Here is some essential advice on what to do when a drive is not recognised.

The different types of hard drive failure

Traditional electromagnetic hard drives can have many types of failures. First, the defective areas of the hard drive, linked to use or shock, lead to slowdowns and errors, resulting in missing files/folders.

When the damaged areas are found in the hard disk's file system, you will be asked to format the partition, which you should not do to increase the chances of recovering data.

If the hard drive is not recognised at all by the system or BIOS, check that the drive does not make any noises either. Clicking, buzzing or scratching sounds are a clear sign of a physical defect that could be the cause of the drive not being recognised by your system. Also, check that the connectors are connected correctly. The intervention of a data recovery engineer will be needed to solve the problem.

External hard drives

Today's external hard drives have the function of a USB drive, but with a larger size and greater storage capacity. This makes transporting large data easier, but the consequence of this advantage is reduced resistance to various hazards.

But beware external hard drives with internal traditional magnetic hard drives, are more susceptible to data loss. The device is sometimes not recognised after a physical shock, exposure to high heat or just not safely removing or ejecting. In most cases, the data recovery procedure for the external drive is the same as for an internal drive or USB stick.

SSD drives, USB sticks, and memory cards: what you need to know.

Unlike mechanical hard drives, SSD drives, USB sticks, and memory cards are based on flash memory. Failure to recognise them may be due to the poor condition of the connectors.

Cleaning them using a cotton swab lightly dipped in alcohol and then allowing them to dry thoroughly may solve the problem.

Alternatively, access may become difficult or even impossible. This is often related to a storage cluster failure. If the SSD drive, stick or card is new, this may be an original defect covered by the warranty. In other cases, it may be due to overuse and wear and tear. It is important to note that flash memories have different write/print cycles that are limited for each cluster, from 1,000 to more than 100,000, depending on the quality of the product. Once this limit is reached, access becomes more difficult, and it becomes an urgent matter to consider saving the data. If the drive becomes completely inaccessible, professional data recovery is necessary.

Unrecognised external hard drive on a Mac

Although often recognised for its superior reliability, macOS can sometimes fail to recognise an external hard drive. First, it is essential to check that the cable is OK. Use a different USB port in case one is faulty. If the drive is detected but not accessible, try repairing the file allocation table with the system's disk utility.

It is enough to click ‘repair disk’ to try to recover the data. If the operation fails, a dialogue box appears to notify you. If the file systems are not recognised, which sometimes happens with older versions of macOS, you should not format as you will risk losing your data.

An unrecognisable hard drive: there is a solution for every challenge

If a drive is not recognised due to faulty areas on the unit, you may want to consider using data recovery software. It is important to note that defective areas on the unit can be caused by mechanical damage and using software can further destroy or harm the data. If it is the drive on which the operating system resides, disconnect it carefully and connect it to another PC to ensure safe recovery. If it is the memory card of a smartphone or tablet, it is best to buy an adapter and connect it to a PC.

Free tools like TestDisk are very effective and offer many tools to recover your files on an unrecognised hard drive. It still requires IT expertise because of its challenging interface. To benefit from an interface that is more intuitive and have the expertise of specialists, our Ontrack EasyRecovery software is an excellent choice.

In the most severe cases, such as after a strong physical shock, immersion in water or great heat, or if it is a drive that cannot be recognised at all, a professional data recovery in a clean room will be needed to rescue all documents, images, etc.

In all cases, when in doubt, it is worth seeking professional advice from specialists to avoid risking losing your data indefinitely.

FAQ about hard drives not being detected

Below are the most frequently asked questions about hard drives that are not recognised.

My hard disk is not accessible but is recognised by BIOS

If your hard disk is running without problems but is not recognised by your computer's BIOS, this could be a sign of a logical error. This type of failure may be due to faulty media or data damage from another source. In this case, first check the jumpers, which vary depending on the configuration of the hard drive. Also check that the connectors and power supply are properly connected. In severe cases, there may be a problem with the circuit board. In most logical failures, you should be able to recover the data with data recovery software.

My hard drive is not recognised and appears dead

A burnt circuit board (PCB) is one of the most common hard disk drive problems. A power surge, overheating or inadequate power supply can cause a hard drive's spindle driver chip to burn, rendering data inaccessible.

In some older models, you can swap the circuit board from another model. But most modern hard drives have circuit boards adapted to the main drive they are made with. In those cases, a data recovery specialist will need to rebuild or transfer the parameters from the faulty PCB to the donor PCB to make it fully compatible with the damaged hard drive.

My hard drive is not detected by Windows

One of the most common questions we hear is, ‘Microsoft Windows on my PC does not recognise my hard drive. What should I do?’. First, restart your computer, check the connections and connect your external hard drive to another PC. If the problem persists, there could be two reasons:

The drive is still not recognised by Windows - If you have checked the connections and connected your hard drive to another PC, but it is still not recognised, the hard drive may be faulty.

The hard disk does not appear in Windows Explorer 10, 7 or 8 but is detected by the computer - There may be a problem with the letter assignment in Disk Management - the hard disk does not have a letter by its name, so Windows Explorer cannot detect the disk partition. Follow these steps to assign a drive letter to it:

Right-click the workstation icon on your desktop

Click ‘Manage’ and then ‘Disk Management’ in the Computer Management window

Select ‘Change drive letter and paths’

In this window, click ‘Add’ to assign a drive letter to the hard disk partition or click ‘Change’ to change the drive letter.

My hard drive is not detected on my Mac

In this case, you should first check whether your external hard drive is recognised by another system. If you have access to a Windows or Linux PC, connect your external hard drive; if it is recognised, perform a repair from the terminal, you can do this with the commands ‘diskutil list’ and ‘diskutil info disk’. Improper removal of the device may cause damage, so make sure you safely remove the disk before disconnecting the external hard drive.

If the external hard drive is not recognised when you reconnect it to the Mac, first check if your USB cable enables the automatic power function of the USB port. If the hard drive is still not recognised, check whether the ‘Finder’ settings allow you to view newly connected devices. If your hard drive is NTFS formatted and not installed on the Mac, you may need to reset the Read Utility (Paragon NTFS is available in most versions of Mac OS). If the external hard drive is still not readable and not visible in the BIOS of other systems (Windows or Linux), a hardware malfunction should be considered.

Why is my external hard drive not recognised by my MAC?

It could simply be that the USB cable is worn out or that the Mac's utility is misconfigured and does not display connected devices. If the hard drive is not partitioned in HFS+ format, the Mac OS X format or ExFat format, check that the utility is installed correctly. If you have checked all the above, there may be a hardware problem. In that case, contact a data recovery specialist.

How do I access an unrecognised hard drive?

It may seem simple, but swap the USB port and check that your USB cable is working properly. If the hard disk appears in the utility but is not accessible, you need to fix it with the terminal commands. If the hard disk is still not recognised, you may need to use a data recovery software to locate the files.

Is updating drivers a solution?

If your hard drive is detected by your computer but does not show up in Windows Explorer, you can try updating the driver. To do this, follow the following instructions:

Open ‘Device Manager’.

Right-click on the start button and then click on ‘Device Manager’. A coloured indicator may appear in this list to indicate any errors.

In the ‘Disk Drive’ section, find the reference of your disk. Right-click on it and then click ‘Update driver’. The update will be automatically taken over by Windows Update.

Do I need to format my hard drive?

You should only format your disk if there is no data (or data you don't need) on it. You should choose the right format to suit your computer. Choose NTFS or FAT32 if you use Windows, and HFS+, ExFat or Mac OS Extended if you use Mac.

Remember that formatting a hard drive erases all stored data, so choose this method only if your hard drive is empty.

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