I'm having the first problem highlighted repeatedly, and it's doing my head in. So sick of removing and reinstalling. Error message as follows.
Unable to create PostgreSQL database: PT3_2011_06_17_081608 Reason: Unable to login to database (template1). Reason: could not connect to server: Connection refused (0x0000274D/10061) Is the server running on host "???" and accepting TCP/IP connections on port 5432?
That error means that the service isn't starting or otherwise is being blocked. If you click Start --> Control Panel --> Administrative Tools --> Event Viewer and go into the event sections at the top left, do you see any errors for PostgreSQL? If so could you copy and paste those error messages here?
I have the same problem where version 8.3.15 will not start. In the event viewer i have three errors with PostgreSQL, all three the same. The error message is:
postgres cannot access the server configuration file "C:/Program Files/PostgreSQL/8.3/data/postgresql.conf": No such file or directory
Locate the file postgres.conf.sample on your machine and copy it to make a new version called postgres.conf in the aforementioned directory and then it should start properly for you.