Unable to Resize Partition Because Access Is Denied in Virtual Disk Manager

I'm attempting to resize a partition that houses the operating system files. I can see the partition in the Disk Management interface and choose Extend Drive with a right-click. It guides me through the panels, but once I click Finish, it says, 'Virtual Disk Manager, Access is Denied.'

Why will you receive the "Access is denied" error message in Virtual Disk Manager when you intend to resize the partition? Usually, two reasons may lead to this problem in the Windows system:

• You don't have the permission to access this partition.
• This partition is a system partition, and there are unmovable system files stored at the end of it.

Now we know the potential factors for being unable to resize the partition because access is denied in the Virtual Disk Manager. Then, I will provide two tested and proven ways to help you fix this issue successfully.

Method 1. Use a 3rd Party to Resize the Partition

The Windows built-in tools have many limitations and restrict many operations. Thus, the fastest way is to use a powerful partition resizing software like EaseUS Partition Master to extend or shrink all the partitions on your hard drive. Follow the specific tutorial below to find out how to use its "Resize/Move" advantage:

Read Also: Fix Unable to Shrink C Drive on Windows 11/10/8/7

Method 2. Change the Partition Permission 

Use the administrator account to change the partition permission and fix the "access is denied" problem.

Step 1. Log in to Windows as administrator and right-click the target drive to choose "Properties" > "Security" > "Edit."

Step 2. Choose the original account and give it full control by ticking the "allow" box.

Step 3. Select "OK" to save all changes.