How to delete locked folders/files? When I try to delete them an error occurs: "Error removing file: Permission denied" I am root. See the image below to know what kind of folders/files.

thanks
Try the following: launch Terminal and enter
sudo rm -rf '/path/to/locked/folder'
And be VERY careful with the path to folder!
Launch your file explorer as root using:
gksudo nautilus
This will open your file explorer, and grant it root, so it should be able to view/delete the directory/file.
If you are like me, and don't care about the warnings in this question you can use this instead:
sudo nautilus
The lock symbol means your user currently have no write permission on the file/folder. To change this:
Properties and then switching to the Permissions tab.Terminal by hitting Ctrl+Alt+t.
Owner of the file (i.e. the Owner field shows your username): add write permission to the owner by running this command: chmod u+w <path_to_file_folder>Owner of the file, but you are in the Group group (i.e. the Group field shows your username or a name of a group to which you belong, e.g. sudo): add write permission to the group by running this command: sudo chmod g+w <path_to_file_folder>Owner of the file and you are not in the Group group: add write permission to the others by running this command: sudo chmod o+w <path_to_file_folder>exitAnd then just delete the file/folder from Nautilus.
Alternatively:
Terminal by hitting Ctrl+Alt+t.
root by running this command: sudo rm -rf <path_to_file_folder>Here is something , that I found was easier to do instead of opening terminal. Right-Click the file and open properties. Then switch to the permissions tab. Then wherever it says Access: change it from whatever it is to Create And Delete Files. This should remove the lock and then you can delete the file normally.