When I ran PostgreSQL on Windows, I did it through cygwin.
In case you're unfamiliar with cygwin, it is a command shell wrapper that gives you a Bash command line interface to your system. What's nice about cygwin is that you can install a lot of standard GNU and unix utilities with it, thus making the cygwin command shell much more useful than the standard cmd.exe that you get with Win2k and XP.
Some useful links:
Postgres users docs:
Postgres administrators docs:
Postgres install docs:
Postgres install on windows docs:
When you install postgres under cygwin, you have to open a cygwin window to start the database. I don't think you can install it as a service.
Best of luck!