An error occurred during the installation.....
iPhone 6s
The message "An error occurred during installation of assembly 'Microsoft.VC80.CRT, type="win32", version="8.0.50727.6195", publicKeyToken="1fc8b3b9a1e18e3b", processorArchitecture=..." may occur because a particular library file is not included in the distribution package supplied with iTunes or won't install for some unspecified reason. Installing the Microsoft Visual C++ 2005 Service Pack 1 Redistributable Package MFC Security Update before attempting to reinstall iTunes may help.
See Troubleshooting issues with iTunes for Windows updates for further advice if required.
tt2
An error occurred during the installation.....