Alienware Power Supply Question

MrBoomBoom

Honorable
Jul 3, 2013
238
1
10,710
Hi!
I am looking at getting an Alienware X51 after having some bad experiences with CyberPower PC. I know I can build a way better system for the same price, but I'm only 14 and my mom won't allow me to build a new computer because she's afraid it might explode XD. Anyway, here's the question:
Does the Alienware X51 come with an external power supply?
If you go to the Personalize tab, under "Power Adapters..." it says "330W adapter" yada yada yada. So, do I have to buy the adapter separately or does it already come with the computer?
Thanks for any help :)