Always on VM under KVM?

I use a clustered KVM installation. When I shutdown a Windows Server 2012R2 VM under virt-manager or virtsh, the VMs shutdown correctly but after a seconds startup automatically! Why? I can't change the memory or vCPU config because I can't stop the VMs. Yes in despair I try virsh destroy VM in an apropriate time, but can't help the VM starts automatically again. Where can I find this settings to turn it off?

Thank you so much!