I know what you mean, whenever I have Limewire running it slows everything down, including my mouse! It jerks all over the place! However when I close Limewire everything runs perfectly! I dont have any idea why, I mean I expect a certain amount of speed loss, not a complete stand still almost though! I have run all my virus scans and spyware doctor things but nothing helps! I know I havent offered you a solution but at least you now know it isnt just you with the problem!