After I found out the QGIS Desktop 2.16.0 with GRASS 7.0.4 icon does work, I copy pasted all dll's from the Grass GIS bin to the QGIS bin. Now the QGIS Desktop 2.16.0 icon works as well!
Next I got a Python error: "Couldn't load QGIS utils. Python support will be disabled."
The answer https://gis.stackexchange.com/a/202200/63260 by Tony Rowlands fixed that too:
"This has been reported as a bug on QGIS (bug number 15279). The reporter says: "the problem is the use of the character "ø" (o-slash) in the directory name for the QGIS program directory: "C:\Program Files\QGIS Nødebo". If you make a name change of the installation directory to ex. "C:\Program Files\QGIS Noedebo" it works without a hitch." I tried this by re-installing 2.16, with the directory name changed C:...to Noebedo..and 2.16 now works perfectly, including loading Python correctly."