How to force delete any unwanted layers ?

When PURGE command failed to remove any unreferenced layers.

When deleting any unused Layers in Layers Properties manager, this message will prompt out;

The solution is by using LAYDEL command,

1 : Type LAYDEL > ENTER

2 : Select the entity on the unwanted layer to delete. This will delete the Layer and all the entities which are assigned to it.

3 : or Type N > Enter

This will prompt you a dialog box with the entire Layers name.  Select the unwanted layers and click OK.