Here is a link to the script as Jay suggested uploaded to my TechNet account. If anyone wants to use this just save it as a batch (.bat) file and it can be silently run in SCCM or anything like it. If you want to run it outside of SCCM you will need to add admin rights to the script or it might not work. The script is notated with REM as to what it is doing. I give no guarentees with this script but it removed it from my users systems with no problem.
https://gallery.technet.microsoft.com/Dropbox-Removal-via-SCCM-063fdd08#content
Hope this helps if it does click the like button.
If you are wondering how I did this so you may apply the same idea to other things in the future I used Revo Uninstaller, ran that for Dropbox where it launched the uninstall I just cancelled then had it scan the remaining registry and folder entries and exported that. I then wrote command for every entry left over in order to achive what you see in that link but first starting out by killing the dropbox process in Task Manager so the folders wouldn't get locked down by users using it and finished it by writing in something to remove desktop icons and start menu pins.