Windows 10 users are complaining about the “Sorry, there was a problem mounting the file” error they encounter when trying to mount an ISO file. Other Windows users experience the same error including those who are using Windows Server 2012 R2, Windows 7, and Windows 8.1.
The Windows operating system comes with a built-in mounter for ISO files. Apparently, the error occurs when users are using this tool. Read on to learn more about the error and how to troubleshoot and finally fit it.
What Causes the “Sorry, there was a problem mounting the file” Error?

There are several reasons we associate this error in Windows 10 but here are some possible causes:
- The ISO file is already mounted
- Drive Letters interfere with the mounting
- MicroSD card is interfering with the mounting
- The ISO file is not set to Read Only
- The ISO file is blocked or the disk imaging driver is corrupted
- ISO file has the sparse attribute set
How to Fix the “Sorry, there was a problem mounting the file” Error on Windows 10
Knowing all those possible reasons for this error helps us determine what could be the next steps in order to fix this issue.
Change the Drive Letter
Errors like this can happen due to conflicting drive letters. In order to eliminate the possibility of it causing this error, you can try to change the drive letter from the Disk Management tool.
- Go to the system menu by pressing the WinKey+X keyboard combination.
- Select Disk Management.
- Then, right-click on the drive you want to change and select the Change drive letter and paths option.
- Click the Change button and do the instructions that follow.
Once you have successfully changed the drive letter, try mounting the ISO file again. If the error is still there, proceed to the next fix.
Remove the Sparse Flag
Setting the sparse flag to 0 will set the file to not spare and then you can start mounting it.
You can do this in two different ways:
Copy the File
When you copy the file, it removes the sparse flag, so in essence, the copied version will mount without a problem. On the other hand, ISO files are large files in gigs of data, so this might not be a convenient option for you.
Use the Command Prompt
You can use the command prompt to remove the flag using the fsutil command.
fsutil sparse setflag yourfilename.iso 0
Verify if the ISO is Already Mounted
Another method to try is to verify if the ISO file has already been mounted. Some users who experience the “Sorry, there was a problem mounting the file” find out that the ISO file they are trying to mount is already mounted. And that’s the reason why Windows is throwing the error in the first place.
You can do this by opening the File Explorer and check if the ISO file is mounted. Sometimes, Windows mounts the ISO files automatically after the process.
Check if the ISO file is Blocked or Corrupted
Normally, Windows 10 will automatically block certain files downloaded from the internet. Even those files that are sent using email can be blocked by the built-in Attachment Manager in Windows 10.
Here’s how you can check if your ISO file has been blocked:
- In File Explorer, right-click on the ISO file and click Properties.
- In the General tab, select the Unblock checkbox and then click the Apply button.
This will unblock the file and hopefully will allow you to mount it successfully.
The default error message for corrupted ISO or IMG files is “The disc image file is corrupted” however, sometimes, it might show you the “Sorry, there was a problem mounting the file” error. So it is better to verify that you are not working on a corrupted ISO file.
If this does not fix the issue, then proceed to the last method below.
Restart the File Explorer
If nothing seems to work, you can try to restart your File Explorer. A lot of times, doing this fixes most errors related to mounting and opening files in Windows 10.
Here’s how to restart the File Explorer (formerly known as Windows Explorer):
- Launch the Task Manager and click on More details.
- Under the Processes tab, look for the File Explorer process and right-click on it. Click Restart from the option.
That’s it! We hope that you have fixed the “Sorry, there was a problem mounting the file” and was able to successfully mount your ISO file. Do let us know in the comments section below.