Adobe Creative Cloud Can't Install due to Another version of Creative Cloud or Adobe Installer

open your activity monitor (mac) or task manager (win) and shut those down.  then clean and reinstall.

clean your computer of cc files per http://www.adobe.com/support/contact/cscleanertool.html
check for, and if available, update your os
repair all ms visual c++ versions that can be repaired.
update your ms visual c++, if it can be updated
restart your computer (don't skip this)
reinstall the cc desktop app, https://creativecloud.adobe.com/apps/all/desktop?action=install&source=apps&productId=creative-cloud
if you're unable to install the cc desktop app at this stage, use the link at the bottom of the page at https://helpx.adobe.com/download-install/kb/creative-cloud-desktop-app-download.html
use the desktop app to install your cc programs/trials