Hello, don't know if this has been covered but I have a problem. After W10 downloaded and installed update kb4100403 my system has become almost unusable. Immediately after the update my system became extremely slow, I had problems with WIFI, my anti virus apps and the icons on the task bar and desktop frequently go away and come back. Has anyone one else seen this behavior? I have an old computer but it was running fine before the update occurred. I have done some research but haven't found my particular problem. Can anyone help me get back to a reasonable running system? Thanks.