Running vCenter Server using a user account
You can use the Microsoft Windows built-in system account or a user account to run vCenter Server. With a user account, you can enable Windows authentication for SQL Server, which provides added security.
The user account must be an administrator on the local machine. In the installation wizard, specify the account name as DomainName\Username. You must configure the SQL Server database to allow the domain account access to SQL Server.
The Microsoft Windows built-in system account has more permissions and rights on the server than the vCenter Server system needs, which can contribute to security problems.
For SQL Server DSNs configured with Windows authentication, use the same user account for the VMware VirtualCenter Management Webservices service and the DSN user.
If you do not plan to use Microsoft Windows authentication for SQL Server, or you are using an Oracle or DB2 database, you may still want to set up a local user account for the vCenter Server system. The only requirement is that the user account is an administrator on the local machine.