I had to perform a couple different updates on my desktop PC running Win 8 Pro in order to run some of the Adobe CC 2014 applications properly, including Illustrator CC 2014. First of all Windows itself needs to be up to date in terms of patches. I updated my video card driver -which seemed to be the thing that solved any issues with Illustrator and Photoshop.
I'm still occasionally running into crash issues at application launch with some other applications, for example Audition did a crash at launch recently. It would still crash at launch even after rebooting. Then I tried right clicking on my Audition icon and selecting "Run As Administrator." It launched just fine doing that.
