Cannot delete folder (which contains several other empty folders)

Don’t worry about the suggestions to start in safe mode or using Process Explorer to look for open handles because that’s not what you are experiencing (if it were, you would be getting a this file is open / locked error, not a permission error).

What you need to do is to assign yourself permission (full-access) in the Security tab of the Properties dialog for the folder. Make sure to assign it to containing folders as well. You may also need to take ownership of the folder before being able to assign permission (in the Advanced section of the Security tab).

If you have difficulty doing this manually, you can install a shell-extension that makes it easier (but beware, it makes it easier for all files/folders).

For the record, those numbered folders are localizations (each number represents a different language), containing files that localize the application for that language. The thing is, usually these folders are deletable my an administrator account unless they have been installed, so it sounds like you are trying to delete stuff from the Windows directory (which is usually a bad idea, and even if you do, they’ll probably be re-created anyway).