I've built a c# compiler using the tutorial on MSDN and a few other resources including here, and I've gotten it to work until I add additional reference assemblies. My errors stem from adding "System.dll" and "System.Windows.Forms.dll" to the ReferenceAssemblies list.

here's my code:

private void SetUpCompilingParameters()
    {
        string ver = string.Format("{0}.{1}.{2}", Environment.Version.Major, Environment.Version.MajorRevision, Environment.Version.Build);
        string libDir = string.Format(@"{0}", Environment.CurrentDirectory);
        string raDir = @"C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\.NETFramework\v4.0";
        string exWpfDir = string.Format(@"C:\WINDOWS\Microsoft.NET\Framework\v{0}\WPF", ver);
        string exDir = string.Format(@"C:\WINDOWS\Microsoft.NET\Framework\v{0}", ver);            

        MyCompiler = new CSharpCodeProvider();
        CompilingParam = new CompilerParameters();
        CompilingParam.GenerateExecutable = false;
        CompilingParam.GenerateInMemory = true;
        CompilingParam.IncludeDebugInformation = false;
        CompilingParam.TreatWarningsAsErrors = false;
        CompilingParam.CompilerOptions = string.Format("/lib:{0}", libDir);
        CompilingParam.CompilerOptions = string.Format("/lib:{0}", raDir);
        CompilingParam.CompilerOptions = string.Format("/lib:{0}", exDir);
        //CompilingParam.CompilerOptions = string.Format("/lib:{0}", exWpfDir);

        CompilingParam.ReferencedAssemblies.Add("System.dll");
        CompilingParam.ReferencedAssemblies.Add("System.Windows.Forms.dll");

    }

As you can see, I've explicitly referenced directories in CompilerOptions but its not helping. I'd like to test the solution on here on stackoverflow that utilizes:

CompilingParam.ReferencedAssemblies.Add(typeof(System.Xml.Linq.Extensions).Assembly.Location);

but I'm having trouble using it for the general System.dll etc...