Symptoms
Fail to install K2 for visual stubdio 2012
Diagnoses
The K2 Blackpearl install refused to install K2 for visual studio 2012 due having the wrong version of Visual studio installed. (Visual Studio Express 2012).
Resolution
Please have a look at the following documentation.
https://social.msdn.microsoft.com/Forums/en-US/0a38f307-33e4-438b-817e-4a41bca927bf/removing-visual-studio-express?forum=Vsexpressinstall
http://www.uninstallapp.com/article/How-to-uninstall-Visual-Studio-Express-Edition.html
You may also have delete some registry files that are referencing VS Express which in turn may allow you to continue with the K2 Install. After that everything should be working in order after getting rid of VS registry files.