Does Kaspersky or Avira slow down the system at all? I was reading some reviews where people said that it drastically slowed their computer down to the point where they had to uninstall them. As well as one review who said he called Kaspersky customer support and they kept pushing him to buy another of their products to speed his computer back up after it being slowed down by their product. Can anyone who has had one or both confirm or deny this? Thanks!