shared_preload_libraries = $libdir/plugins/plugin_debugger.dll causes server not started

Hi - I am new to Postgresql. I installed Postgresql on my Windows 7 laptop, and things run fine until I tried to turn on the debugger using the methodology illustrated in this link:
http://www.postgresonline.com/journal/archives/214-Using-PgAdmin-PLPgSQL-Debugger.html

1. shared_preload_libraries = $libdir/plugins/plugin_debugger.dll in the file postgresql.conf

2. Install the file pldbgapi.sql in the database

3. Restart your PostgreSQL server process

I tried re-starting the process (actually the service that runs the server), I got the message: "The operation could not be completed, access is denied".
I then shut down my machine, and when it is back again, the service Postgresql-x64-9.3 is still STOPPED, and could not be started.
I used pgadmin3 to connect to the server Postgresql, and got this message:

Server doesn't listen
The server doesn't accept connections: the connection library reports
could not connect to server: Connection refused (0x0000274D/10061) Is the server running on host "localhost" (::1) and accepting TCP/IP connections on port 5432? could not connect to server: Connection refused (0x0000274D/10061) Is the server running on host "localhost" and accepting TCP/IP connections on port 5432?

Thanks in advance for your thoughts/recommendations on how to fix this problem.

Michelle