Well, you have to keep a single fast and anti virus updated system for connection between the internet and another systems that are not connected with internet just like gateway to handle communication with net and the systems to update them,
I have installed the Window 8 and window 7 but it running smoothly and give me the options to select either of the two windows , but I do not select the window 7 window automatically go with window 8 . The same process I followed shrink the drive-then install that window 8 in the specific drive and reboot the system and it showed me the both options.