I am unclear on why you would uninstall because an updater didn't work?
If you mean the check for updates button didn't detect a new version thats because the version it checked was only updated on Wednesday afternoon.
Now onto your problem, uninstalling Decor8 should have no impact on any running programs. I would check to see if the Decor8 folder still exists. If it does still exist then delete the contents and reboot. If the files are in use and cannot be deleted, simply rename them, reboot and you will be able to delete.
If the folder is empty then Decor8 is not doing anything on your machine and it is unlikely Decor8 has anything to do with your problem.