Trying to delete a file or folder and unable to delete?
Window error suggests that file or folder is open by any program?
All permissions on file and ACLs look good and you technically have full access?
So what is using the file or folder and why?
Usually you could have a file opened by a program and closed but program may retain link to the fail until you close the program so try closing all open programs.
Again, pretty much every time you reboot your computer it works but in a busy life rebooting computer should not be today's requirement and why you can literally do anything and everything without a single reboot on Linux/Unix operating systems.
So you need to really find what program has the file open in Windows. This is not a built in feature of windows so you can't do it out of the box. You will have to download an extended Process Explorer from SysInternals that was bought by Microsoft since they started to know more about Windows than Microsoft so better eat that fish.
The MS KB Article 242131 suggest the procedure how to find the programs that have open files.
So you simply download SysInternals Process Explorer from Microsoft's site. Extract it into a folder, my favourite is "c:\program files\process explorer" and run the executable.
Simply click on Find from menu or binoculars icon and type the file name. This will give you exactly the where the file is being used. If you close or kill that process you will get the access back to the file or the folder it contained in.