AsmSpy A simple command line tool to view assembly references. Download AsmSpy.zip: http://static.mikehadlow.com/AsmSpy.zip. The zip file contains AsmSpy.exe. How it works: Simply run AsmSpy giving it a path to your bin directory (the folder where your project's assemblies live). AsmSpy D:\Source\sutekishop\Suteki.Shop\Suteki.Shop\bin It will output a list of all conflicting assembly references. That is where different assemblies in your bin folder reference different versions of the same assembly. To see a list of all assemblies and all references, just add the 'all' flag: AsmSpy D:\Source\sutekishop\Suteki.Shop\Suteki.Shop\bin all The output looks something like this: .... Reference: System.Runtime.Serialization 3.0.0.0 by Microsoft.ServiceModel.Samples.XmlRpc 3.0.0.0 by Microsoft.Web.Mvc 4.0.0.0 by Suteki.Shop Reference: System.Web.Mvc 2.0.0.0 by Microsoft.Web.Mvc 3.0.0.0 by MvcContrib 3.0.0.0 by MvcContrib.FluentHtml 3.0.0.0 by Suteki.Common 2.0.0.0 by Suteki.Common 3.0.0.0 by Suteki.Shop 2.0.0.0 by Suteki.Shop Reference: System.ServiceModel.Web 3.5.0.0 by Microsoft.Web.Mvc Reference: System.Web.Abstractions 3.5.0.0 by Microsoft.Web.Mvc .... You can see that System.Web.Mvc is referenced by 7 assemblies in my bin folder. Some reference version 2.0.0.0 and some version 3.0.0.0. I can now resolve any conflicts.