What version did you have before?
Did you uninstall the old version? If so, how?
Uninstalling (through the CC software) and reinstalling (also through the CC software) will probably solve your problem.
If not, more info will be needed.
I had after effects cc before I upgraded to the 2014 version. Then I uninstalled it (the old version) through control panel and checked through the adobe cleaning tool.
Well, if uninstalling AE and reinstalling doesn't work, you can try removing everything Adobe-related, running the CC Cleaner tool, and then reinstalling.