[Change to Secure File Delete]

Oh, forgot to state my Mac uses 500gb of flash memory, should this make a difference t possible settings??

 

Many thanks

[Change to Secure File Delete]

Having just bought the Pro Version can't seem to change my settings;

CCleaner shows secure deletion is set at "Normal" (Faster)... 

I have tried to click the change this to "Secure" (Slower), but this feature and the overwrite preference box is greyed out and currently shows complex overwrite 35 passes, as per the screen shot...

 

Does anyone know how to change this over to secure, please??

 

Thanks in advance