Proxmox VE 3.1 Windows Install with 1 Core

Hey Proxmox Community,

i try to install Windows 8 with 1 vcore KVM64(default) but the system dont install.

After a Reboot during install the System freeze. I try other CPU type but all the same
after the Reboot on Install the System freeze.

Can i only Install Windows with 2 Cores?

Regards,
mike