Can't get wordpress to update

3.8.3 updates say:

Unpacking the update…

Verifying the unpacked files…

Preparing to install the latest version…

The update cannot be installed because we will be unable to copy some files. This is usually due to inconsistent file permissions.: wp-admin/images/w-logo-white.png, wp-admin/images/se.png, wp-admin/images/post-formats.png, wp-admin/images/marker.png, wp-admin/images/w-logo-blue.png, wp-admin/images/comment-grey-bubble-2x.png, wp-includes/js/mediaelement/bigplay.png, wp-includes/js/mediaelement/background.png, wp-includes/js/mediaelement/controls.png, wp-includes/js/tinymce/themes/advanced/img/colorpicker.jpg, wp-includes/js/tinymce/themes/advanced/skins/wp_theme/img/mce-more-2x.png, wp-includes/js/tinymce/themes/advanced/skins/wp_theme/img/mce-nextpage.png, wp-includes/js/tinymce/themes/advanced/skins/wp_theme/img/embedded.png, wp-includes/js/tinymce/themes/advanced/skins/wp_theme/img/mce-more.png, wp-includes/js/tinymce/themes/advanced/skins/wp_theme/img/mce-nextpage-2x.png, wp-includes/js/tinymce/themes/advanced/skins/wp_theme/img/gallery.png, wp-includes/js/tinymce/themes/advanced/skins/wp_theme/img/gallery-2x.png, wp-includes/js/tinymce/plugins/wpeditimage/img/delete.png, wp-includes/js/tinymce/plugins/wpgallery/img/delete.png, wp-includes/images/admin-bar-sprite-2x.png, wp-includes/images/admin-bar-sprite.png, wp-includes/images/wpicons-2x.png

Installation Failed

What should I do?