DS is quite an invasive program, not only does it install things to atleast 3 places on your system, but it also adds quite a bit of info to the registry.

@ Sheedee, I suspect that it's the content directories that are your problem, the directories don't exist any more but DS is still listing them. The safest & easiest way to remove them is to start up DS and go "Edit > Preferences" (or press F2), select the Directories tab and remove all of the pathways listed for each of the 3 formats DS caters for, click apply & then accept buttons once your finished and then close DS. This will cause DS to update the registry and remove the pathways from it, however DS3 doesn't like not having any directories listed, so don't be to surprised if you find the default (My)Documents directories listed when you next start DS.