I have tested each memory module and get the same thing (Rebooting) so have put all 4 modules back in. A mate has given me an old-ish cooler master 550w psu and this seems fine so far. Its at the very minimum for my spec though. Wont be on Skyrim or Battlefield 4 for a while I think. Don't want this one blowing too.
Alienware 17 R4 2017 review