We have Kaspersky Internet Security suite on some of our computers at home. It has been really nice, much less intrusive than Norton and McAfee and seemingly out of the way. We’ve not been caught by a virus and have been very happy with it. Unfortunately they just released the new 2013 version and that all changed. Suddenly just logging off your account would take 10-20 seconds and things all around became very slow. Our computer is a 64-bit dual-core 2.61GHz AMD with 4GB memory – plenty of power per their requirements. I even followed the steps they recommend to resolve this (which also lower your security), but it had no impact. I even went a bit beyond that just to see, but no luck. I finally removed it and re-installed the 2012 version and now everything is fine.
It shocks me that a company could produce something that is so degraded (whether knowing it was or not). It reminds of me a product called Word Perfect.