A language which can't deal with UTF-8 nowadays is simply put: crap!
The same goes for Microsoft's WiX Toolset which isn't able to handle UTF-8 at all…
WiX - http://wix.sourceforge.net/
It's open source (common public license 1.0), produces standard MSI/MSM installers, and the UI is completely customisable. It can be "double click on the installer, watch the progress bar, you're done" or be used to produce the Microsoft Office installer. (Don't do that for a game.)
It doesn't have a drag'n'drop GUI, and the "source" for the installer is XML files - which may upset some people. But, on the other hand, you can include it in your build system - so when you rebuild a file, the installer is updated as well.
There is WPKG out there, but I'm sure it's not official enough for most people also, I had some trouble finding the software packages that I wanted. It is the apt for MSI files that's missing from Windows.
I think windows is hurt in that there's not a pre-installed packager on systems. I've built things using WIX but it's a major drag. If they had a nice built-in and easy to use packager then perhaps there'd be more of a culture of packaging things on Windows.