It appears to be installed. C:\Program Files\Microsoft SDKs\Windows\v8.0A\bin\NETFX 4.0 Tools>gacutil -l Npgsql Microsoft (R) .NET Global Assembly Cache Utility. Version 4.0.30319.17626 Copyright (c) Microsoft Corporation. All rights reserved.
The Global Assembly Cache contains the following assemblies: Npgsql, Version=2.0.12.0, Culture=neutral, PublicKeyToken=5d8b90d52f46fda7, processorArchitecture=MSIL Number of items = 1 2012/11/26 Francisco Figueiredo Jr. <francisco.figueiredo...@gmail.com> > gac -l Npgsql
