As far as I know you should not just put fonts into the Windows font folder, you should install the fonts in Windows. This can be done by right-clicking the font and selecting Install.
When installting a font in Windows you will be asked if the font shall be copied to the fonts folder, but I think that is optional.
(When using Windows Explorer it might be that a drag and drop of an font into the fonts folder will automatically initiate an install, but since that folder is likely not writable by a regular user I think it's a bad way to do it.)