zadadka

I know from Microsoft (http://technet2.microsoft.com/WindowsVista/f/?en/library/8fdf5f32-26b6-47c3-ad6b-a09790f07c6e1033.mspx) that an unattended upgrade is possible, but does anyone know where I insert this instruction, whether in the Autounattend.xml, or using WSIM ? thanks