SP6 replaces Service Pack 5 for developers using Visual Basic 6.0, Visual C++ 6.0, and Visual SourceSafe 6.0. (Developer using Visual InterDev 6.0, Visual J++ 6.0, and Visual FoxPro 6.0 should continue using Service Pack 5.) Intall processor pack on sp6: http://support.microsoft.com/kb/872907