This windiows installer went wrong on me.
First, it tried to uninstall, it offered to uninstall from 'C:\D'. My DMD install is 'C:\dev\D'... The path was presented in a greyed out textbox that I couldn't type in to correct it, and no button to select the true install location.
The uninstall step failed.
Then when reinstalling I was given the option where to install, I chose 'C:\dev\D' and it installed over the top of my existing install, and wiped my sc.ini file. So I need to configure the DirectX SDK paths again.
Side note:
I still think the installer really should detect the DXSDK; it's a Microsoft library, and virtually any multimedia software developed with VS2010 or prior will depend on it (It's merged into the WinSDK since DX2012).
The DXSDK install paths are:
Include: C:\Program Files (x86)\Microsoft DirectX SDK (June 2010)\Include
Lib: C:\Program Files (x86)\Microsoft DirectX SDK (June 2010)\Lib\x64
The "(June 2010)" part is a safe assumption, it's the last released one, and it will remain so since it's now bundled with the WinSDK for more recent visual studio releases. It's the only one available on the Microsoft website.
As I see it, if we profess to support VS2010 and prior, then we should detect the DXSDK paths in the installer, otherwise software that builds fine in VS2012+ won't work with VS2010 without user intervention, and that will almost certainly lead to posts on this forum.