Nebruz

Hi Guys I host a Windows 2008 R2 server from home and I had the exact same problem. this is what i did to fix.
– I gave my wp-content folder IIS_IUSRS modify permission
– I added the line define(‘WP_TEMP_DIR’, ABSPATH . ‘wp-content/tmp/’); to my wp-config.php file
– then made the following changes to my wp-includes/class-http.php file
from this:

// Force some settings if we are streaming to a file and check for existence and perms of destination directory
		if ( $r['stream'] ) {
			$r['blocking'] = true;
			 if ( ! is_writable( dirname( $r['filename'] ) ) )
				 return new WP_Error( 'http_request_failed', __( 'Destination directory for file streaming does not exist or is not writable.' ) );
		}

to this:

// Force some settings if we are streaming to a file and check for existence and perms of destination directory
		if ( $r['stream'] ) {
			$r['blocking'] = true;
			 if ( ! is_writable( dirname( $r['filename'] ) ) )
			 if ( ! call_user_func( 'WIN' === strtoupper( substr( PHP_OS, 0, 3 ) ) ? 'win_is_writable' : 'is_writable', dirname( $r['filename'] ) ) )
				 return new WP_Error( 'http_request_failed', __( 'Destination directory for file streaming does not exist or is not writable.' ) );
		}

as found here.
This worked for me but i don’t know if it is an official fix.