On the contrary mbsamart, I think you should leave Windows Defender running, as kaspersky doesn't catch many spyware related items, especially the lower end ones like cookies and certain malware. When they said it isnt a good idea to have 2 programs, they meant 2 spyware-centric applications. Kaspersky is not one of those, so it would still be in your best interest to have some sort of antispy app running.