Using Postgres as a "embedded" / SQL Lite database on Windows

Hi Everyone I have a question re using postgres as a "embedded" database on
Windows.

First a little background:
I have been using Postgres for a number of years on Linux, and it is great.
I am now working with a company which develops Windows software using
Delphi. This has been successful and they have a number of users (1000's).
This currently uses a Paradox database. For various reasons (some I am sure
you can guess!) we would like to move away from paradox, and Postgres is a
good option.

The main problem(s) I see with Postgres in this environment related to:
- The fact that the users are very non computer savy - these are general
office workers or Farmers - most will have little interest in the computer
beyond getting a job done.
- Installation (Yes there is a silent install)
- running as a service
What happens in the unlikely event that they already have a version of
Postgres installed?
- I guess I can see that we could create a installation which works for
most users, but end up spending a lot of time getting the last few computers
updated, as we deal with some obscure problem between windows and services
and Postgres (I know welcome to Windows), and we would like to be able to
manage these updates remotely

I would like to hear feed back from others, has anyone else deployed
Postgres in this type of environment?
Are there options for running postgres, maybe as a process (maybe the wrong
term) within the main application - this could be started and stopped by the
application?

I am thinking some type of options similar to SQLLite would be great for a
single user install - but we also want to be able to A) use the full power
of Postgres, B) set-up as a full server in some other cases.

I look forward to hearing your views
Thanks
Craig