Install/Use NpgSQL on Visual Studio 2010. I'm trying to connect to a Postgres 9.5 database using VB. NET/VS2010. I've got the 4.5 framework installed and the project is targeting "Framework 4". I used Npgsql-3.2.5to install the and referenced the dll, but was unable to build the project, or see any of the NpgSQL objects.