How can I force .NET to use a local copy of an assembly that’s in the GAC

Make sure the GAC Assembly and local Assembly have different version numbers (not a bad idea to let your build number, at least, auto-increment by wild-carding your AssemblyVersion in AssemblyInfo: [assembly: AssemblyVersion(“1.0.0.*”)] ). Then, redirect your assembly binding using your app’s config:

• http://msdn.microsoft.com/en-us/library/2fc472t2(VS.80).aspx
• http://msdn.microsoft.com/en-us/library/433ysdt1(VS.80).aspx.

In your case, you won’t need the “appliesTo” attribute of the assemblyBinding config. You just need something like:

<runtime>
    <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
        <dependentAssembly>
            <assemblyIdentity name="YourAssembly" publicKeyToken="AAAAAAAAAAAA" culture="neutral"/>
            <bindingRedirect oldVersion="0.0.0.0-5.2.1.0" newVersion="5.0.8.1"/>
        </dependentAssembly>
    </assemblyBinding>
</runtime>