removing all traces
I use software to check all registry changes when installing software I've downloaded and want to check out.
Then when I unload them and throw them away as I do with 90% of them I try to clean up after them and remove all traces.
But I can't do that. It's obvious that some of them know they've been here before. So they must have left something behind, somewhere.
How do they do that? What do they leave?