I don't know where people got the impression that Windows will always take the entire HDD for itself
MS taking control and the line
" We are the microsoft . Resistance if futile , your own unique ...... "
is from the XP days ( even then there is a ,and rather well hidden, already checked check box to install to the whole drive .If you uncheck it you can install to only a partition )
but it is pre checked "for your convenience "
the win 7 installed dose have the option to select where to install win 7
though i think it is buried on a submenu .
though i think most people just assume MS will " borg" the system , because that is the default settings
if you the user do not check things , do not make sure that it is doing what YOU want it to do
and do not do your " do diligence "
and CHECK things before you say "YES" to EVERYTHING
then bad things WILL happen !