As soon as data is erased, they cannot be displayed anymore. However, unless data is SafeErased, the data is still accessible.
If you run the analysis function after the deletion, you will see the remaining files.
The success of O&O SafeErase can also be measured with special data rescue programs. You can use O&O DiskRecovery for this purpose. These program will show you what data may be restored. You can download O&O DiskRecovery as trial versions for free from our Website.
More information about their use can be found in their respective user handbooks. If you have any questions. don't hesitate to contact us.