you can check information of config file and log file to find the reasons.

Start Your Postgresql and Openerp services in windows using the below command,

                       Start --> Run --> services.msc Enter  and start the both service.

And check in Postgresql pgAdmin "openpg" user is available. If not create the user   "openpg" and  password "openpgpwd" [that given in the installion time].  restart the server and check the result.

Hello,

I have the same problem, thus i post here (i hope it's good).

I have downloaded this executable http://nightly.openerp.com/trunk/nightly/exe/openerp-allinone-setup-8.0dev-latest.exe.

The installation occurs well and when i write localhost:8069 in my web browser it indicate me : connection failed ...

I have check in services.msc as indicated on your answer and the service PostgreSQL_For_OpenERP is running but openerp-server-8.0 not. I start it but after few seconds he stop. Maybe the problem is there but i don't know how to resolve it.