an error occurred while starting the task sequence 0x80070032

The active system partition on a MBR system must be NTFS

and

Failed to prepare the system partition for staging.
The request is not supported. (Error: 80070032; Source: Windows)

and

Failed to stage WinPE. Code(0x80070032)

So, I did the steps informed in the other thread to press F8 durcing the Error and used the following in the DOS Box:

1. Diskpart
2. Select Disk 0
3. Clean

After that steps, the Bootprocess worked perfect. It seams that the Disk was partitioned not that good, that WinPE could handle it.

Rerun the task sequence and the installation will begin. Of course, these commands can be scripted. Copy the following commands to a text file:

select disk 0
clean
exit

Save the text file and name it cleandisk.txt or any name you want. Copy this text file to the root of your Task Sequence Media (e.g. the root of a flash drive). Then edit your Task Sequence. Under Install Operating System, click Add / General / Command Line and fill in this line:

diskpart.exe /s X:\cleandisk.txt

Now your system disk will be automatically cleaned before the OS is installed.