I don't believe so, there might be the directory left in Programfiles with your node file and a few others settings. (which you could delete) If you were to decide to uninstall D2OL.

Now if you decide to continue to run, then every 6 hours (or if you click on manual update) it will upload all the work you've done so far and download more work. The other sticky's in this section talk about this more

jjcom