VMware vCenter SSO: MSSQL not supprted with Windows Authentication

I strongly recommend you to read VMware KB2034918 before installing vCenter SSO.
You definitely have to navigate to the "SSO database questions" section where you can read following sentence:

"Can I use Windows Authentication for the MSSQL database user name and password, as the JDBC Setup screen implies?

No. For MSSQL databases, you must use SQL Server Authentication database users. Windows Authentication users are not supported. For more information, see Connection to the MSSQL database fails during vCenter Single Sign On installation section of the VMware vSphere 5.1 Release Notes"

And now you can safely run installer, proceed to the Database Information and make sure you won't tick the most visible check-box out there...:)

Designed for future usage only...:P