Sometimes, when attempting to mount an ISO image in Windows, you may encounter the error:
Couldn’t Mount File. Sorry, there was a problem mounting the file.
This article explains how to fix the issue with mounting an ISO image to a virtual CD/DVD drive in Windows.
You can also extract the ISO using a standard archiver by following our instructions starting from step 2.
1. Check ISO File Attributes
If Windows cannot mount the ISO, check if the file has the SPARSE attribute set. Open a Command Prompt as an administrator and run:
fsutil sparse queryflag "D:\Distr\Windows10-22h2_clean.iso"
If the command returns This file is set as sparse, remove the attribute:
fsutil sparse setflag "D:\Distr\Windows10-22h2_clean.iso" 0
Verify the attribute status using the fsutil sparse queryflag command. It should return This file is NOT set as sparse.
If you encounter the error Error: Access is denied when modifying the attribute:
Disable the Read-only attribute in the file properties:
Or run the command:
attrib -r "D:\Distr\Windows10-22h2_clean.iso"
If the ISO file was downloaded from the internet, unlock it through its properties. On the General tab, check the Unblock checkbox. Then try mounting the ISO image again.
In some cases, a simple solution is to copy the ISO file to another directory or a local drive if it was on a network resource.
2. Reset CD/DVD Drive Settings in the Registry
Incorrect CD/DVD drive settings may cause errors when mounting ISO files. To reset the settings:
1. Open regedit.exe.
2. Navigate to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4D36E965-E325-11CE-BFC1-08002BE10318}.
3. Delete the UpperFilters and LowerFilters parameters.
4. Restart the computer.
If the UpperFilters.bak parameter is present, do not modify it.
3. Issues with Mounting ISO Files from Windows Explorer
If the ISO file mounts successfully using the PowerShell command:
Mount-DiskImage
but fails to mount via Windows Explorer, reset the file associations for ISO files:
1. Right-click the ISO file and select Open with.
2. Choose Windows Explorer and check the option Always use this app to open .iso files.
Try restarting Windows Explorer via Task Manager or with the command:
tskill explorer & explorer
4. Check the Length of the ISO File Path
If the path to the ISO file exceeds 213 characters, it may cause a mounting error. In such cases, the file may mount successfully, but unmounting may require restarting Windows.
