When an external hard drive is detected by your PC but the files cannot be opened—or Windows reports the drive as RAW, unallocated, or inaccessible—your immediate priority must shift. You are no longer trying to "fix" the hard drive; your only goal is to recover your files.
The golden rule of data recovery is simple: do not format, initialize, repartition, or save anything to the affected drive. Any of these actions will overwrite the hidden data you are trying to save.
As long as the drive does not have a catastrophic mechanical failure (like shattered internal platters), a dedicated third-party recovery application can usually bypass Windows File Explorer and extract your data directly from the raw sectors. Here is exactly how to do it safely.
Check the External Hard Drive Before Attempting Recovery
Before buying software or panicking, rule out a simple connection failure. A bad cable can mimic a corrupted file system.
- 1. Try Another USB Port: Connect the drive directly to the back of your PC motherboard. Avoid front-panel ports, USB hubs, or keyboard pass-throughs, which often fail to provide enough power to mechanical drives.
- 2. Replace the USB Cable: Test the drive with a known-good, compatible data cable. Check whether the drive becomes stable afterward.
- 3. Test the Drive on Another Computer: Plug the drive into a different PC or a Mac to determine whether the problem is specific to your Windows installation or the drive itself. Note: Do not repeatedly reconnect a drive that makes clicking or grinding noises.
- 4. Check Disk Management: Right-click the Windows Start button and select Disk Management. Look for your drive in the bottom list to confirm whether Windows detects the physical hardware. Identify its status: is it RAW, Unallocated, Offline, Not Initialized, or Healthy but missing a drive letter?
Do Not Format an Unreadable Drive
Do not click Format if the files are important. Formatting creates a brand-new, empty file system over the top of your old one, making data recovery significantly more difficult (and sometimes impossible for fragmented files).
Similarly, if Disk Management prompts you to Initialize the disk or create a new partition, click Cancel. Writing any new structural data to the drive is dangerous right now.
Recover Data From the Unreadable Drive
When Windows File Explorer cannot access the partition, you need third-party data recovery software. Modern recovery tools are designed to scan RAW volumes, deleted partitions, and corrupted sectors by ignoring the broken file system and looking for the raw file signatures underneath.
1. Install the Data Recovery Software
Choose a reputable recovery tool (such as EaseUS, Disk Drill, Recuva, or TestDisk). Crucial step: Download and install the software onto your computer's internal C: drive. Never install recovery software onto the unreadable external drive, as the installation files will overwrite your lost data.
2. Connect the External Hard Drive
Connect the drive directly to the computer. Open the recovery software and wait for it to detect the physical drives. Select the external drive by its physical name or capacity (e.g., "Seagate 2TB RAW") rather than immediately looking for a visible drive letter.
3. Start a Scan
Begin with the Standard/Quick Scan when available. This parses the remnants of the file table and is usually very fast. If the required files are not found, run the Deep Scan. Deep scans take much longer (sometimes hours), but they search sector-by-sector to find files even when the partition information is completely destroyed.
4. Find the Missing Files
Once the scan populates, do not just scroll aimlessly through millions of files. Use the software's file-type filters (e.g., Pictures, Documents, Video). Search by specific filenames if available. Check the recovered folder structure, and always Preview the files before recovery to ensure they are actually intact and not corrupted.
5. Recover the Files to Another Drive
Select the most important files first. When you click "Recover," you must choose a different internal or external drive as the destination. Never save recovered files back to the unreadable drive. Verify that the recovered files open correctly on your PC after the process finishes.
If the First Scan Cannot Find Your Files
- Run a Deep Scan: If you skipped it earlier, you must run it now. Allow the scan to finish completely before judging the results. If the original folder structure was destroyed, you will likely need to search the deep scan results by file type (e.g., all
.jpgor.pdffiles grouped together). - Look for the Lost Partition: Some software has a specific "Lost Partition Search" feature. Check whether the software can detect the older partition boundaries on the physical disk rather than only scanning the current RAW volume.
- Create a Disk Image: If the drive is unstable, repeatedly disconnecting, or incredibly slow, scanning it directly is dangerous. Use the recovery software's "Byte-to-Byte Backup" or "Disk Image" tool to clone the failing drive to a healthy, larger drive. You can then safely run recovery scans on the image file instead of stressing the failing physical disk.
If the External Drive Is Making Clicking or Grinding Sounds
Stop using the drive immediately. Disconnect it. Do not repeatedly restart or rescan it. Do not run repair commands, and absolutely do not attempt to open the hard-drive enclosure yourself.
Software cannot repair failed heads, seized motors, or scratched platters. If the files are irreplaceable, you must send the drive to a professional clean-room data recovery service. Continued use of a clicking drive will permanently destroy the data platters.
Should You Run CHKDSK Before Recovering the Files?
No. CHKDSK (Check Disk) is a Windows command-line tool designed to repair file-system problems so Windows can mount the drive again. It is not designed to recover lost files safely.
If CHKDSK encounters a corrupted file or an orphaned data cluster, it will frequently delete it or truncate it to "fix" the file system structure. Do not make this your first step when important data exists only on the unreadable drive. Prioritize copying, imaging, and data recovery first. If your files are safely backed up elsewhere, file-system repair can be considered afterward.
What to Do After Recovering the Data
Once you have verified that your recovered files are safe on a different drive, you can deal with the broken external drive.
- Check the External Drive: Test its health using a SMART monitoring tool like CrystalDiskInfo. Determine whether the problem was a one-time file-system corruption (often caused by unplugging the drive without safely ejecting) or actual hardware sector degradation.
- Reformat Only After Recovery: If the SMART health is "Good," you can use Disk Management to recreate the partition and format it back to NTFS or exFAT. If the drive continues to throw errors, throw it away. Do not trust a failing drive with important files.
- Create a Backup: Keep your important files in at least two physical locations going forward. Use another external drive, network-attached storage (NAS), or a cloud backup service. Do not treat a single external drive as your only copy.
When Data Recovery Software Is Not Enough
Software recovery has limits. You will need to contact a professional data recovery lab if:
- The drive is completely undetected by Disk Management across multiple computers.
- The drive repeatedly connects and disconnects every few seconds.
- The drive makes clicking, grinding, or beeping sounds.
- The drive has suffered physical damage (dropped, water damage, fire).
- Connecting the drive causes the entire computer to freeze until you unplug it.
- The files are absolutely irreplaceable and the drive health is rapidly deteriorating during the scan.
Frequently Asked Questions
Can I recover data from an unreadable external hard drive?
Yes. As long as the computer's Disk Management utility can detect the physical drive, data recovery software can usually scan the raw sectors and recover the files, even if the partition is corrupted.
Should I format an external hard drive that Windows says needs formatting?
No. If you format the drive, you will overwrite the file system and make it much harder to recover your lost files. Ignore the Windows prompt and use recovery software first.
Can data recovery software recover files from a damaged partition or RAW drive?
Yes. Most modern recovery tools feature "Deep Scan" modes that ignore the damaged partition table entirely, searching the drive sector-by-sector for known file signatures (like the headers of JPG or PDF files).
Where should I save recovered files?
Always save recovered files to a completely different drive (like your PC's internal C: drive or a second external hard drive). Saving files back to the damaged drive will overwrite the very data you are trying to rescue.
Should I run CHKDSK on an unreadable external hard drive?
Not if you value your data. CHKDSK prioritizes fixing the file system structure over saving your files, and it may delete orphaned file fragments to "repair" the drive. Recover your data with software first.
Final Thoughts
Recovering data from an unreadable external hard drive is all about following a strict workflow: stop writing to the drive → check whether Windows detects it → scan with recovery software → preview → recover to another drive.
Do not let the Windows "You need to format the disk" prompt scare you into making a destructive mistake. If the drive is simply suffering from logical corruption, software can usually save the day. However, if the drive shows any signs of physical failure like clicking or freezing your PC, stop all software recovery attempts immediately and consult a professional data recovery lab.
