Although Visual Studio and other applications appeared to remain in working order after the (very time consuming) Windows Update installation of windows10 tech preview, none of my Intel software tools except Impi came up by themselves. The culprit appeared to be multiple visible versions even though the latest had been installed with the choice to replace the previous. Impi also had 2 visible versions, but that didn't stop it from coming up. Un-installing everything possible and re-installing seemed to recover, but then I had to find a working ifort.cfg elsewhere.
The current free start-button (with default options) seems necessary to have reasonable options. I couldn't see even how to run Visual Studio otherwise.
I compared the working of Intel compilers with VS2012 pro and VS2013 free and didn't see much difference, although in CL compilations there are a few different missed optimizations in the two versions (on an early corei7 desktop).