Windows XP Power User Security Group Memberships

In Windows XP Professional, security rights were categorized into distinct tiers to balance administrative capability with system stability. Power user rights were primarily granted through membership in the local Power Users group, as well as the Administrators group, which inherently included all lower-tier permissions. This article examines the exact security group memberships that provided power user capabilities, the specific rights conferred by them, and how domain accounts interacted with these permissions.

The Local Power Users Group

The primary security group designed specifically for this access level was the built-in local Power Users group (BUILTIN\Power Users). Windows XP Professional created this group locally on every standalone workstation and domain-joined machine.

Adding any local user account to this group immediately granted the user elevated capabilities beyond standard user restrictions without granting the full control reserved for administrators.

The Administrators Group

Members of the local Administrators group (BUILTIN\Administrators) also possessed full power user rights. Because Windows XP security operated on a hierarchical model, administrator accounts held a superset of all permissions granted to Power Users, including complete control over the operating system, file system, registry, and security policies.

Domain Group Memberships

In an Active Directory domain environment, domain user accounts did not possess local power user rights by default. To grant power user rights to domain accounts on a Windows XP Professional client:

• Direct Local Mapping: The domain user account had to be explicitly added to the local machine’s Power Users group.
• Domain Group Nesting: A domain security group (such as a custom Workstation Power Users group) could be added to the local machine's Power Users group via Restricted Groups in Group Policy or manual local computer management.

Rights Granted to Power Users

Membership in the Power Users group granted specific user rights and file system/registry access that standard users lacked. These permissions included:

• Software Installation: Installing applications, provided the installer did not modify core operating system files or register kernel-mode drivers.
• Hardware Configuration: Installing and managing local device drivers, such as printers, modems, and network adapters.
• System Management: Adjusting the system time, timezone, and power management options.
• Resource Sharing: Creating and managing local shared folders and shared printers.
• Account Management: Creating, modifying, and deleting local user accounts and local groups, with the restriction that Power Users could only modify accounts they personally created. They could not modify accounts in the Administrators group.
• File System and Registry Permissions: Read and write permissions to portions of the %ProgramFiles% directory and the HKEY_LOCAL_MACHINE\Software registry hive, allowing legacy software to run without administrative elevation.