I don't know whether to laugh . . . or what!
I have never heard of stuff being downloaded without user input!
The best way to prevent any downloads is kill all the downloadds in the dwonloads panel of the search pane,then go to the library pane and selectt the incompletes and use the delete button. Then quit LimeWire.
sounds like time to delete the incomplete folder and run a virus checker.
sorry for laughing--most people post about troubles with no or slow downloads.