Rename Administrator Account with Group Policy
The built-in local Administrator account ships with two predictable properties: well-known RID 500 (predictable SID) and the literal name 'Administrator'. The Accounts: Rename administrator account security policy lets you change the name across every domain-joined computer with one GPO. This article walks the workflow: create a Computer-scoped GPO linked to the OU containing your endpoints, navigate to Computer Configuration / Policies / Windows Settings / Security Settings / Local Policies / Security Options, set Accounts: Rename administrator account with a deliberately neutral name (Operator, BuildAcct, etc.), run gpupdate /force on a target, verify in Computer Management - Local Users and Groups. Includes the GPO naming convention (C_ / U_ / CU_), the names to avoid (Admin, SuperUser, anything containing 'admin'), and the common pitfalls (linking at the domain root, picking a guessable name, confusing the local rename with the Domain Administrator rename).