domain. Restartable Active Directory allows ADDS to be stopped and restarted from the Management Console or the command-line without rebooting the domain controller. This reduces downtime for offline operations and reduces overall DC servicing requirements with Server Core. ADDS is implemented as a Domain Controller Service in Windows Server 2008. All of the Group Policy improvements from Windows Vista are included. Group Policy Management Console (GPMC) is built-in. The Group Policy objects are indexed for search and can be commented on. Policy-based networking with Network Access Protection, improved branch management and enhanced end user collaboration. Policies can be created to ensure greater quality of service for certain applications or services that require prioritization of network bandwidth between client and server. Granular password settings within a single domain - ability to implement different password policies for administrative accounts on a "group" and "user" basis, instead of a single set of password settings to the whole domain. Failover Clustering Windows Server 2008 offers high availability to services and applications through Failover Clustering. Most server features and roles can be kept running with little to no downtime. In Windows Server 2008, the way clusters are qualified changed significantly with the introduction of the cluster validation wizard. The cluster validation wizard is a feature that is integrated into failover clustering in Windows Server 2008. With the cluster validation wizard, an administrator can run a set of focused tests on a collection of servers that are intended to use as nodes in a cluster. This cluster validation process tests the underlying hardware and software directly, and individually, to obtain an accurate assessment of how well failover clustering can be supported on a given configuration. This feature is only available in Enterprise and Datacenter editions of Windows Server. Disk management and file storage The ability to resize hard disk partitions without stopping the server, even the system partition. This applies only to simple and spanned volumes, not to striped volumes. Shadow Copy based block-level backup which supports optical media, network shares and Windows Recovery Environment. DFS enhancements - SYSVOL on DFS-R, Read-only Folder Replication Member. There is also support for domain-based DFS namespaces that exceed the previous size recommendation of 5,000 folders with targets in a namespace. Several improvements to Failover Clustering (high-availability clusters). Internet Storage Naming Server (iSNS) enables central registration, deregistration and queries for iSCSI hard drives. Self-healing NTFS: In Windows versions prior to