WordPress: Upgrade error due to inconsistent file permission

While upgrading WordPress running on Microsoft Windows Server 2012 R2 from 4.6 to 4.7, I ran into error about file permission.

In short,

1. TEMPORARILY add WRITE security permission to IIS_IUSRS local group for wordpress folder
2. Run upgrade successfully, then
3. Remove WRITE security permission of IIS_IUSRS local group from wordpress folder.

WordPress: Temporary security persmission settings to upgrade

Downloading update from https://downloads.wordpress.org/release/wordpress-4.7-new-bundled.zip…

Unpacking the update…

The update cannot be installed because we will be unable to copy some files. This is usually due to inconsistent file permissions.: wp-admin/includes/update-core.php

Installation Failed

Check PHP error log: C:\Windows\Temps\PHP70x64_errors.log

[19-Dec-2016 12:04:29 UTC] PHP Warning:  copy(C:/wordpress/wp-admin/includes/update-core.php): failed to open stream: Permission denied in C:\wordpress\wp-admin\includes\class-wp-filesystem-direct.php on line 257

Downloading update from https://downloads.wordpress.org/release/wordpress-4.7-new-bundled.zip…

Unpacking the update…

Verifying the unpacked files…

Preparing to install the latest version…

Enabling Maintenance mode…

Copying the required files…

Disabling Maintenance mode…

Could not copy file.: index.php

Installation Failed