uninstall everything cc including the cc desktop app.
clean your computer of cc files per http://www.adobe.com/support/contact/cscleanertool.html
restart your computer (don't skip this)
reinstall the cc desktop app, https://creative.adobe.com/products/creative-cloud
use the desktop app to install your cc programs/trials
Nope this does not work!!
what do you see now when you try to open pre?
I don't have Premier, I have PS and LR. The standard white error box with Error 16. But I resolved the issue by clicking on photoshop.exe and going to properties, then selecting something like "Always open as administrator" or "Open as administrator". Click ok and it worked.