Task sequence has failed with the error code (0x800700A1). For more information, contact your system administrator or help desk operator.
Quick look up for Windows error code to 0x800700A1 showed;
0x800700A1 = BAD_PATHNAME
Most likely task sequence engine will through the Task sequence has failed with the error code (0x800700A1) error msg after making changes to the local hard drive (removing or adding a new drive to VM). Also when there is a step in task sequence to copy files to local hard drive before the drive partition step in OSD may show above error. The task sequence tries to copy the files to local hard drive but cannot find the path as the drive is in RAW state.
To resolve this issue;
The drive need to be formatted before continuing with the task sequence.
Follow below steps to format the target machine hard drive;
Restart the target machine into task sequence using the PxE or boot media.
On the welcome to the task sequence wizard, press F8, then run the following commands in the command prompt.
Create partition primary
Select volume 1
Format fs=ntfs quick
Restart the target machine and boot into the task sequence, which should continue without any errors