Robot Framework can't find Python
I faced the same issue. 
Install a different bit version of ROBOT framework. In my case, I was first trying to install 64bit version but it said  "No Python installation found in the registry." 
Then I tried to install the 32bit version of ROBOT framework and it worked.
So there is nothing wrong with your Python version.
I'm trying to install Robot Framework, but it keeps giving me an error message during setup that "No Python installation found in the registry."  I've tried running the installer as administrator, I've made sure that Python is installed (I've tried both 2.7.2 and 2.7.9), and both C:\Python27 and C:\Python27\Scripts are added to the PATH (with and without slashes on the end, if that matters).
I have no idea why it can't find Python.  What do I need to do?