This policy setting prevents users from adding new Microsoft accounts on this computer. If you select the Users cant add Microsoft accounts option, users will not be able to create new Microsoft accounts on this computer, switch a local account to a Microsoft account, or connect a domain account to a Microsoft account. This is the preferred option if you need to limit the use of Microsoft accounts in your enterprise. If you select the Users cant add or log on with Microsoft accounts option, existing Microsoft account users will not be able to log on to Windows. Selecting this option might make it impossible for an existing administrator on this computer to log on and manage the system. If you disable or do not configure this policy (recommended), users will be able to use Microsoft accounts with Windows. Counter Measure: Configure this policy setting to Users cant add or log on with Microsoft accounts. Potential Impact: Users will not be able to log onto the computer with their Microsoft account. Fix: (1) GPO: Computer Configuration\Windows Settings\Security Settings\Local Policies\Security Options\Accounts: Block Microsoft accounts (2) REG: HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Policies\System!NoConnectedUser