I had the same exact problem with my Dell latitude E6430, it kept restarting the computer at the TS (right before the Welcome to the Task Sequence Wizard where you put your password). What I did to fix the problem was a) Go to dell driver website put my asset tag# c) download the network NIC driver d) in SCCM SOftware library=> Drivers=> Import drivers then i added the NIC driver to the boot x64 e) after that i ran the TS again and it worked. Turns out to be the problem with Dell Latitude E6400 Series.