OSX: Allow connection from remote host (actually from windows running in parallels)

I am trying to connect to my OSX installed version of PG from Windows XP SP3
running in Parallels on my mac.

When I try to connect, i get an error about no entry in the pg_hba.conf for the
ip i am trying to connect to.
I used pgAdmin3 to try to edit the file. postgresql.conf first to enable to the
pg_hba.conf dir and then the pg_hba.conf file.

Neither allows me to edit and save these files due to permissions.

I also tried to edit them through the terminal, that didnt work and also added
my user to the people allowed to read/write those two files.
Then through a text editor, it seemed to work (as well as doing it again through
pgAdmin) and then when saved, PG would not start back up.

So what is the correct process to edit these files and allow pg to be connected
to by remote host.

Thanks.
Bill

(tried posting this on the forums and got the same errors not allowing me to do
so)