I'm thinking of removing/re-installing Platinum, in order to straighten out some errant file locations, and basically clean things up.
I had X3 on my laptop as well, which I tried to uninstall using the control panel, add remove programs. I didn't realize at the time that I could access the uninstall file through the command center. I still have the X3 folder with a bunch of files in it.
 
I'm considering doing the uninstall of Platinum, as I mentioned, through the CCC. My question would be, what is the best way to re-install? I have all of the Platinum download files on my external drive, which I downloaded when I first upgraded to Platinum.
Would you recommend installing from the command center, or directly from the downloaded files, which I'm thinking will give me more control over the destinations. 
Thanks for any direction!

Hi. I did a clean install of SONAR from files on my external HD via CCC when Win10 came out. Download the latest CCC. Open CCC, click on the gear icon, click verbose install (will give you options for installation).Click on the Paths tab, and locate your files folder (on your external HD) and set as Download Path. Set your preferred Vst and Content path, and you should be good to go. Hope it helps.
All the best

Clean reinstall instructions:
https://www.cakewalk.com/Support/Knowledge-Base/2007013392/SONAR-2015-Clean-Install-Instructions