Question : "replace permission entries on all child objects.... "access denied error message

I'm trying to just set the permission on different folders for different groups.
When I select the "replace permission entries on all child objects with entries shown here that apply to child objects", I get the following error message for different files, "an error occured applying security information to......(path and filename) Access is denied".
So on all those files and folders that I get that error message, no security settings are applied, so If I have to do each one manually, it's a major pain.  Does anyone know why I'm getting this error message on all sorts of different folders?

Answer : "replace permission entries on all child objects.... "access denied error message

i figured it out, I first have to take ownership of the folder, this way, it will give me ownership of all files and folders, and then I can assign access to whom ever I want.  If I don't take ownership and just assign the access, it won't be able to access those folders or file.
Thanks for your suggestion.