I have exactly the same problem. I think that what happens here is that although VB6 APPEARS to install (and actually runs OK), because it hangs at the end of setup it is not registered as an installed program on the system. It does not appear as an intalled program, so you can't even uninstall it on my machine. So...when SP6 is trying to install it can't find the VB6 installation. That's my theory, but I can't find the solution, so I hope that with this added bit of info someone can resolve it! Incidentally, I have a completely trouble-free installation on Windows 7 64-bit, so its obviously a Windows 8 problem rather than a 64-bit issue.