How to modify an operating system like these:

Hi, there’s a lot of modified operating systems floating around the internet; like these:
Windows Vista SP2 Alien Edition V2 x86 + Office2010:
http://www.google.com?t=2797714&highlight
and
Windows Vista Gamer� NVIDIA Edition R1 x32/64
http://www.google.com?t=2413497&highlight=
but I was wondering how do they get about creating these?
Any1 know or got any links to websites… I’ve had a quick look and cant find any for myself really.
Thanks in advance!
Answer #1
http://www.google.com.au/search?hl=en&q=Making+an+Unattended++XP&btnG=Google+Search&meta=&aq=f&oq=
Answer #2
Hmm, the name for a modified OS is “unattended”?
Thanks for the link
Answer #3
Check, which can most probably be located on that google search unattended.msfn.org/