Admin questions on NT

I have set up 7.0.3 on my NT machine (no hope for non-Microsoft at this time) at
my place of employment. I set it up as user "larryb". The larryb account has
Administrator privledges, something (as I understand) had to be in order to
install a fully  functional cygwin. Now, because I installed 7.0.3 as larryb,
the user larryb is the Postgres DBA-superuser, right? I'm wondering/worried that
because I did not install as the user "postgres", an NT account that has no NT
Administrator privledges, I'm screwed security-wise. Does the superuser have to
be postgres? Can a non-NT Administrator even install cygwin?

LB