How to Register .Net assembly into GAC using InstallShield 2010

Deploying .Net assemblies into Global Assembly Cache can be done using either regasm.exe tool  in .Net SDK or using InstallShield IDE. This article discusses them in detail

Using Assembly Regstration Tool (regasm.exe) - Basic MSI, Installscript MSI & InstallScript Projects

• User 'System Search' inInstallShield IDE or FindAllFiles() in script to locate the regasm.exe from 'C:\WINDOWS\Microsoft.Net\Framework', which will set the path to a property variable (already defined in property manager) 
• Register -> Use the property variable to invoke regasm.exe
  Syntax -
  regasm <Assembly file name with path>  /codebase /tlb:<AssemblyName>.tlb
  [Note: The above command registers all public classes contained in <AssemblyName>.dll, and generates and registers the type library <AssemblyName>.tlb, which contains definitions of all the public types defined in <AssemblyName>.dll.]  
• For InstallScript Project, 'System Search' is not available in IDE, so we can use InstallScript to reigster assembly using regasm.exe
  if ( FindAllFiles ( WindowsFolder ^ "Microsoft.NET" ^ "Framework", "regasm.exe", svResult, RESET ) == 0 ) then
           svPath = INSTALLDIR ^ "<AssemblyName>.dll /codebase /tlb";
           LongPathToQuote ( svPath, TRUE );
           if (LaunchAppAndWait ( svResult, svPath, WAIT ) < 0) then
                  MessageBox (" Unable to launch " + svPath + ".", SEVERE);
           endif;
  endif;
• UnRegister-> Use the property variable to invoke regasm.exe
  Syntax - regasm.exe -u <Assembly file Path>

 Using Installshield IDE - Basic MSI & Installscript MSI Projects

• Open the new or existing Installshield project from which you need to register an assembly into cache.
• Go to Tools -> Options -> Preference Tab ->  Self Registration and keep the following two items selected.
• Com Extraction will occur during the build time

             [Note: If this item is not selected, then you would get the following error at runtime
               'Error 1935 An error occurred during the installation of assembly component  <Component GUID> HRESEULT 0x800700B07]

• Create a component and add the assembly to be registered into GAC to the new component and set it as a key file.
• Set .Net COM Interop property to 'YES'
• For Windows Installer projects (Basic MSI and InstallScript MSI), each component contained in the project has a .NET COM Interop setting. Setting this option to Yes will run regasm.exe against the component's keyfile at build and import the registry information into the built installation. If the destination for the component is [GlobalAssemblyCache], the /codebase parameter is passed as needed to regasm.exe at build time.
• InstallShield 2009 / 2010 uses the regasm assembly from the path stored in 'DotNetRegasmPath' under HKEY_LOCAL_MACHINE\SOFTWARE\InstallShield\15.0\Professional
• Build & test the installer to see the new file registered into GAC.