local folders sync in win 8

Hi guys
I'm new to acronis, I've been using nero backup and syncing my personal folders to a portable hard drive which is simple and gives me immediate confirmation that individual files exist.
Using acronis I'm trying to sync my docs folder to the same named folder on a portable hard drive but keep getting an error message saying the folder is already being used by another sync and therefore doesn't complete the setup process. the only other sync visible doesn't seem to be active as nothing is apparently (how would I know) being copied from one folder to another. I also can't seem to delete this original sync to start again?
Hope someone can help
JJ