In cases with high cpu utilization by ekrn.exe, we'd need to need the following: 1, if the problem occurs with advanced heuristics and runtime packers disabled in the real-time protection on access (default setting) Response: It's better with Advanced Heurisitcs and runtime packers disabled in real-time protection. With those enabled it's literally hopeless (but probably VERY secure 2, if setting the real-time protection to scan files with default extensions instead of all files (default setting) makes a difference Response: That does not make much of a difference. The worst problems I have is accessing large archives using a third party file manager like FreeCommander. But I do not want to give up all my productivity tools because my AV doesn't like them 3, if the problem goes away after uninstalling ESS/EAV. Since all http/pop3 traffic is routed through ekrn.exe, you might see ekrn utilizing the cpu instead of that application (e.g. a known bug in Windows Installer, see http://support.microsoft.com/kb/916089 for details) Response: I am not sure what ESS/EAV is and how to uninstall it. I am not using e-mail scanning at all, but I do notice when I download with either Opera or Firefox that when the file download completes ekrn.exe gets really busy doing it's thing to the extent that it slows down the whole browser. And btw, I am running Vista Ultimate SP1. I really want to be a happy user, but this is driving me nuts right now..