When you enlarge your virtual hard disk, you must also enlarge your guest operating system's partition to take advantage of the additional space.

Fusion resizes the guest operating system's partition when you resize the virtual hard disk. If you held down the Option key when you clicked Apply to resize the disk, you can manually resize the Windows partition. For Windows Vista and Windows 7 or later, you can use the operating system's Disk Management tool to resize a partition.


Verify that your virtual hard disk is big enough to accept the increase in partition size. See Resize a Hard Disk.


  1. Right-click Computer and select Manage.
  2. Double-click Storage.
  3. Double-click Disk Management.
  4. In the list, right-click the partition to expand and select Extend Volume.
  5. Follow the prompts to resize the partition and click Finish.
    The partition item in the Disk Management pane displays its new size.
  6. Close the Computer Management window