Undo Disks Settings
Using the Undo Disk Settings, you can enable and configure the Undo Disks feature.
Note: This option can be enabled or disabled only when the virtual machine is not running.
The Enable Undo Disks option allows you to discard or apply the changes you made to the virtual machine's hard disk during your working session. If you choose to discard them, the changes will be discarded when you shut down the virtual machine. When you start this virtual machine again, its virtual hard disk will have the same data it contained before you started the previous working session. If you choose to apply the changes on the virtual machine shutdown, the next time you start this virtual machine, its virtual hard disk will store the changes you made during the previous working session.
Note: When enabled, the Undo Disks feature is applied to all virtual hard disks this virtual machine uses.
You can choose whether you want to discard the changes you made to the virtual machine's hard disk or choose the action to perform in the On shutdown field.
Notes: 1. You cannot create snapshots of virtual machines that have this option enabled.
2. This option cannot be enabled for the virtual machines using the Boot Camp partition.
If you want to prevent Virtual Machine Configuration from further unauthorized changes, click the Lock icon at the bottom of the window. The next time someone wants to change the settings on any pane of Virtual Machine Configuration, an administrator's password will be required.