Fixing the error : Unable to read from the source file or disk

Digital file storage is incredibly reliable these days, but that doesn’t mean something can’t go wrong from time to time. You might be opening or copying a file in Windows when suddenly you get a “Cannot read source file or disk” error message, akin to an unwanted Halloween prank.

It can be frustrating to find that your precious data seems to be inaccessible, but there are many means to prevent you from giving up on recovering your information!

This bug always disrupts your plans because you can’t copy, delete or transfer a file, and it usually happens at the most inopportune times. This problem cannot be put off, it has to be solved here and now, and the chances of recovering your documents are high.

So read on and choose the most appropriate method.


What causes the “Can’t read source file or disk” problem

What causes the "Can't read source file or disk" problem

Before finding the best solution to the “Can’t read from source file or disk” problem, you need to familiarize yourself with the possible technical reasons related to the source disk that lead to the error. Here are some of the causes that have been mentioned in detail.

  • Bad sectors on the source disk. A bad sector damages the disk and makes data inaccessible. As a result, an error message is displayed, i.e. it cannot be read from either the source file or the source disk. Any data stored on a disk with bad sectors can lead to consequences such as data loss.
  • Windows system errors can cause the source file or disk to become unreadable. These system errors can be caused by corrupt system files or a corrupt partition containing those files.
  • An insufficient power supply is another cause. Any power surge in either direction, i.e. increasing or decreasing the power supply can cause an error. The problem may also be caused by the drive circuit board, as it is sensitive to power surges. Also, if you are using an external hard drive, it needs a proper power supply to perform functions such as copying, moving, or deleting data. This is because the connected external hard drive receives power from the device.
  • A bad connection to an internal hard drive via a SATA cable or an external hard drive (USB) via a loose connection can cause an error, i.e. the original file or drive cannot be read. This will make the disk/hard drive inaccessible.
  • File size limitation is also associated with the list of causes of the “Can’t read source file or disk” error. If the file size is too large to copy, you will get an error message popping up. In some cases, the FAT32 file format supports a file size of 4 GB. Therefore, any data that exceed the 4 GB limit will not be copied to this file format.
  • An unsupported filename, i.e. a filename that is not recognized by the drive, will also result in an error message indicating that the original file or drive cannot be read. If your device cannot identify the filename during a file search, you may get an error message. This happens when the file name is not compatible with the operating system.
  • A damaged source file is a possible cause that can lead to an error. A corrupt source file will not be recognized or accessible by the device and the File Explorer utility. The partition or the entire disk will be corrupted.


To fix the “Cannot read source file or disk” error

To fix the "Cannot read source file or disk" error

Fixing incompatible file systems

NTFS is completely different from FAT32 and can easily handle large files. FAT32 is an older file system. If the disk being transferred is a FAT32 disk, the maximum file size it can handle is 4 GB. If the file to be transferred is close to this size, problems may arise.

  1. Select the disk containing the file you want to copy.
  2. Right-click on the file and select Properties.
  3. Identify the file system.
  4. Repeat the process for the destination disk.

If both file systems are NTFS, go to Fix #2.

Usually, you can’t copy large files to FAT32, but there have been cases where someone has used a file separator to split a file into smaller pieces and then the file on the drive is corrupted. The Windows operating system does not recognize that the file has been split and just reads the large or corrupted file.

Fixing bad sectors

A sector is part of the memory. When formatting a hard drive, part of the process is to divide the drive into separate sections that will be used independently to store data or to store large files together.

Check for damaged sectors :

  1. Select the hard drive you are trying to copy from.
  2. Right-click and select Properties, then select the Tools tab.
  3. Click the Validate button.
  4. Let the process run.
  5. Repeat the procedure for the target hard drive.

The disk check is self-contained and will alert you if it finds damaged sectors and can repair them in most cases. However, this process can damage the file you are trying to move. So be aware of this before you do it.

Restore file permissions
  1. Right-click on the file you are trying to copy and select Properties.
  2. Click the Security tab, and then click Change in the middle.
  3. Click the Add Middle button.
  4. Enter your computer user name in the box below and select Check Names.
  5. Select OK. This returns you to the previous screen.
  6. Select the user name in the top window, then select the check box next to Full Control in the bottom window.
  7. Select Apply, then select OK.

Windows should now allow you to move the file at will without giving you a “Cannot read source file or disk” error.


Frequently Asked Questions

  1. Connect the device to your PC.
  2. Type "Control Panel" in the search box.
  3. Click the "Administrative Tools" button.
  4. Click on the "Computer Management" button.
  5. Click the "Disk Management" button.
  6. Right-click the drive or device you want to format and click "Format".
  7. Select the file system and set the cluster size.

To fix this, you need to reboot your system and then boot into safe mode. Try copying the files in safe mode; if you still cannot copy the files, it means that the PST file is corrupt.

For Windows 10, here's how to do it: hold down the Windows key and press "r", type "cmd", then press "Enter", type "cd ... / ...", then press "Enter", type "tree" and press "Enter". This usually displays all the files on your hard drive.

Reboot your computer. If you can't read the source file or drive when copying in Windows 10, and this is the first time this has happened, try restarting your computer (don't turn it off or on, just reboot). Restarting helps the computer to handle these errors on its own and brings it back to its normal operating state.