VirtualBox has 2 snapshot recovery options- Revert a Snapshot and Discard a Snapshot.

Be careful, these two options are very different.

NOTE: If you only have ONE snapshot, then either option will return you to the previous state before that snapshot was taken.

With multiple snapshots:

• Revert a Snapshot allows you to use the snapshot before the current snapshot you are using at the moment, but the current snapshot is still stored.
• Discard a Snapshot deletes the current snapshot. Now, you must use the snapshot before the one you just deleted. and your system will be returned to that previous state.