It can be alarming when you open your computer and notice that some or all of your drives seem to have vanished. There are a few potential reasons why your drives may not be showing up as expected.
Your drive isn’t properly connected
The most straightforward reason a drive might be missing is if it has become physically disconnected from your computer. Here are some things to check:
- Make sure both ends of the SATA cable or power cable are firmly inserted into the drive and motherboard/power supply if it’s an internal drive.
- For external drives, check that the USB or Thunderbolt cable is securely plugged into both the drive and computer.
- Try connecting the drive to a different SATA, power, USB, or Thunderbolt port on your computer if possible.
- Inspect the cables for any loose wires or damage.
- If it’s an external drive, try using a different cable if you have one available.
Reconnecting the drive properly may be all that’s needed to get it to show up again.
Drive isn’t turned on
External hard drives and SSDs sometimes have a separate power button or switch that needs to be turned on before the drive will function. Double check that your external drive is turned on and connected to power if needed.
Drive isn’t properly mounted
Drives connected to your computer need to be “mounted” to become accessible to the operating system. Usually this happens automatically, but sometimes the operating system fails to mount a connected drive properly. Here are some steps to try manually mounting the drive:
- Open Disk Utility (on Mac) or Disk Management (on Windows)
- See if the missing drive appears here but just isn’t mounted
- Select the volume and choose the Mount option
This should make the drive accessible if it’s showing up in Disk Utility/Disk Management but just hasn’t been mounted correctly.
BIOS settings or motherboard issues
For internal hard drives, issues with BIOS settings or your motherboard could prevent a drive from being detected. Here are some options to investigate:
- Check that the SATA operation mode in BIOS is set to AHCI, not IDE.
- See if the drive shows up in the BIOS hardware/device list.
- Try updating to the latest motherboard BIOS version if available.
- Reset BIOS settings to default if corrupted settings are possibly preventing drive detection.
If the drive fails to show up even in the BIOS, the drive or motherboard itself may have developed a fault.
Outdated disk controller drivers
Having outdated disk controller drivers can prevent connected drives from functioning properly. To update them:
- Open Device Manager on Windows or System Information on Mac
- Expand the Disk Drives section
- Right click on the disk controller/SATA controller device and choose Update Driver or Update Drivers
Be sure you have the latest drivers direct from your motherboard or disk controller manufacturer’s website.
Drive failure
If you’ve verified all the connections are good, updated relevant drivers, and checked for motherboard issues, the unfortunate possibility is a drive hardware failure. Some signs include:
- Unusual noises coming from the drive
- Smoke or smells coming from the drive enclosure
- Frequent crashes and file corruption
A certified repair technician may be able to recover data from the failed drive, but otherwise purchasing a new replacement drive would be recommended.
Windows drive letter conflict
In Windows, drives are assigned letters like C:, D:, E: etc. If a drive is disconnected and another takes its place, this can cause a drive letter conflict when reconnected and prevent it from showing up properly. To resolve:
- Open Disk Management
- Right click on the inaccessible drive and choose Change Drive Letter and Paths
- Assign it to an unused letter
This should make the drive accessible again under the new letter assignment.
Drive doesn’t have a partition
For a new drive to show up and be usable, it needs to be partitioned and formatted first. This might be the case if you see unallocated space in Disk Utility/Disk Management. To fix:
- Right click on the Unallocated space
- Choose New Simple Volume and go through the partition creation wizard
- Select a volume size and file system (NTFS for Windows, APFS/Mac OS Extended for Mac)
Once partitioned and formatted, the drive should show up like normal.
Damaged file system
If a drive’s file system becomes corrupted or damaged, the operating system may fail to read it even if the drive seems to still be connected. Symptoms include very slow performance and inability to access saved files. Options to try:
- Run CHKDSK in Windows or First Aid in Mac Disk Utility to check and repair file system errors.
- If necessary, reformat the drive with a new partition and file system.
- Use data recovery software to rescue files before reformatting.
Drive is disabled in Device Manager
Drives that are having problems will sometimes be automatically disabled by Windows Device Manager. To re-enable:
- Open Device Manager
- Expand the Disk drives section
- Right click on the problematic drive and select Enable
Hopefully after enabling it the drive will be accessible once again.
Power or data cable failure
Damaged power or data cables can cause drives to malfunction or fail to show up entirely. If you suspect a faulty cable, try replacing it with a new one. External drive cables tend to deteriorate over time from frequent flexing and movement.
Insufficient power supply
HDDs and SSDs draw power from your PSU or external power adapter. An underpowered unit could potentially cause connectivity issues. Ensure your PSU has enough wattage and your external drive power adapter is rated appropriately.
Outdated USB drivers
For external USB drives, out of date USB drivers can prevent proper functionality. To update them:
- Open Device Manager
- Expand the Universal Serial Bus Controllers section
- Right click each USB device/hub and choose Update Driver
Be sure to get the drivers directly from your motherboard or laptop manufacturer’s website.
Conflicting programs or antivirus software
Some software programs and antivirus packages are known to sometimes interfere with drive connectivity. Try temporarily disabling your antivirus or uninstalling any recently added programs and see if the drive shows up again.
Drive shows up in BIOS but not Windows/MacOS
If you can see the drive in BIOS but not within your operating system, the drive likely requires partitioned and formatted before it will become accessible. Follow the steps above to partition and format the drive with Disk Management in Windows or Disk Utility on a Mac.
External drive shows up in Device Manager but not File Explorer
For external drives connected via USB that show up in Device Manager but not Windows File Explorer, you may need to assign a drive letter to the volume. Open up Disk Management and assign a letter to get it to show up in Explorer.
Drive detected but reports 0 bytes capacity
A drive showing up but reporting 0 bytes likely has a partition problem. You’ll need to delete all partitions on the drive and recreate a new one from scratch. Backup any needed data first before deleting partitions.
Drive not recognized on front USB ports
Some users have reported external drives showing up properly only when connected to rear USB ports and not front panel ports. Try using the rear motherboard USB inputs if possible.
Need to replace SATA cable or power cable
If no connections are loose and drives are specified as enabled in the BIOS, you may need to replace a faulty SATA data or power cable. Test connectivity with a different cable to confirm.
Can’t detect second hard drive
Multi-drive setups generally need the SATA operation mode in BIOS set to AHCI rather than IDE. Ensure AHCI mode is enabled if trying to connect more than one internal drive.
Thunderbolt cable needs replacement
Thunderbolt cables gradually wear out with repeated inserting and removal. Replace the Thunderbolt cable if you’ve confirmed the drive and computer Thunderbolt ports are working properly.
Conflicting drive letters
If connecting an additional external drive, it may be assigned the same drive letter as an existing volume. Open up Disk Management and change the letter of the new drive to an unused letter.
Bad sectors or corruption on the drive
Extensive bad sectors or file system corruption can potentially prevent a drive from being recognized. Scan for errors with CHKDSK or a disk repair utility. Reformat if needed after recovering data.
Need BIOS update to support large drives
Very old systems may have BIOS limitations preventing drives over a certain capacity from being detected. A BIOS update might be required to support large modern drives.
Insufficient USB power
Some external USB hubs and ports provide limited power, which could potentially prevent higher power drives from functioning properly. Try a rear port, powered hub, or Y-cable.
Incorrect SATA mode configured in BIOS
Make sure the SATA operation mode is set correctly in BIOS per your drive type – either AHCI or RAID. Incorrect mode can prevent detection.
Drive is waiting to be initialized
Brand new drives will show up as Unallocated in Disk Management. Right click and select Initialize Disk to start the initialization process before partitioning and formatting.
USB chipset needs driver update
Outdated USB drivers, especially USB 3.0 drivers, may result in connectivity issues with external drives. Update chipset drivers from your motherboard OEM’s website.
External drive draws too much power
If your drive requires more wattage than your USB port provides, consider using the drive’s included power adapter or a powered USB hub to ensure sufficient power.
Thunderbolt port needs driver update
Keep Thunderbolt drivers updated through Windows Update or your laptop manufacturer’s website to prevent potential external drive connectivity problems.
Common troubleshooting steps
To summarize, here are some of the basic first troubleshooting steps to try when your drive isn’t showing up:
- Check all connections and cables
- Try a different cable if possible
- Reseat connections and restart computer
- Check for loose/damaged wires
- Update motherboard BIOS
- Update disk controller drivers
- Make sure drive is powered on
- Verify sufficient power supply
This will cover many of the common basic problems that might be preventing a drive from being properly detected.
When to seek professional data recovery
If you have exhausted all other troubleshooting steps and believe the drive has experienced complete failure, you may need to enlist the help of professional data recovery experts. Symptoms like the following suggest physical failure:
- Unusual noises coming from drive
- Visible damage like dents or cracked casing
- Burnt smell from drive
- Clicking or beeping sounds
- Drive making internal spinning motions but not detected
Professional recovery labs use specialized tools to dismantle drives in clean rooms and attempt extracting the data at the platter level. This can be an expensive process but may be able to save irreplaceable data in the case of a serious failure.
Preventing drive issues
You can take proactive steps to minimize the chances of a drive failure down the road:
- Always eject and safely disconnect drives before moving computers
- Use the Safely Remove Hardware icon before unplugging external drives
- Keep drives away from environmental hazards like moisture, static electricity, heat, and strong magnets
- Make sure drives are mounted securely in desktop PCs during transport
- Be gentle and don’t bump or drop drives
- Only use manufacturer approved cables and power adapters
Closely following drive handling best practices will optimize longevity and reliability.
Recovering data from the failed drive
Before formatting a failed drive or disposing of it, you’ll of course want to try recovering any important files and data. Options include:
- Trying data recovery software to see if files can be pulled off
- Sending to a professional recovery service if the data is highly valuable
- Taking to a local repair shop for an in-person recovery attempt
- Removing the drive and installing in another PC enclosure to access the data
If there is absolutely no way to access the drive contents, unfortunately the data may be lost permanently if no backups exist.
Conclusion
Drives not showing up properly can lead to temporary panics but fortunately there are a number of troubleshooting steps you can take to get them back online. Check your connections, cables, power, BIOS settings, and OS drivers as a starting point. Seek professional data recovery assistance if the drive seems to have completely failed physically. With the right systematic approach, you should hopefully be able to get your missing drive to reappear and regain access to its precious data.