Changing Snapshot Options

Select: VM > Settings > Options > Snapshot

On this panel, you can do the following:

You can disable snapshots for the virtual machine. The virtual machine cannot have a snapshot in order for snapshots to be disabled.
To disable snapshots for this virtual machine, check the Disable snapshots check box.
You can view the date when the snapshot of the virtual machine was taken.
You can lock the snapshot (so that you cannot accidentally overwrite it with a new snapshot)
To lock a snapshot, check the Lock this snapshot check box.