Question : Sccm OS deployment: Bootmgr is missing.

I'm trying to deploy Vista 64bit Enterprise with SCCM.
I've added the Operating System WIM-image to SCCM and distributed it to distribution points, I've made task sequence and advertised it to a collection where is a computer added by MAC association. I've also made a bootable USB stick to access SCCM infrastructure.
When I boot from usb stick everything goes fine, correct advertisement is found and installation starts. When system is booted during the installation I get this error: BOOTMGR IS MISSING.
I suspect that the problem is that there are no correct Diskpart commands. These are the commands I used when Vista was deployed without sccm:
diskpart
select disk 0
clean
create partition primary
select partition 1
active
format
exit

How can I add these commands to task sequence? Or is it possible that the problem is something else?

Answer : Sccm OS deployment: Bootmgr is missing.

I ran these commands before OS deployment via sccm and the installation was successfull:

diskpart
select disk 0
clean
create partition primary
select partition 1
active
format
exit

So how can I add these diskpart commands in task sequence?