Windows Defender aborts with the following error message: The Windows Defender service on Local Computer started and then stopped. Some services stop automatically if they are not in use by other services or programs. The start option is Manual and will not retain the Automatically option once I try to start the service; it defaults back to Manual. I have checked Event Viewer, there are no error messages. All Dependency services are running (DCOM Server Process Launcher and RPC Endpoint Mapper). I have tried to do a Repair using the installation disk, but no errors were found. I am running Microsoft Security Essentials as my antivirus program. This is a fresh install of Windows 7 Ultimate 64 bit with all current updates applied.

DWheim, When you install Microsoft Security essentials on your machine. The installation of MSE disables Windows Defender because MSE does the same as windows defender + ofcourse antivirus scanning. Check also the following Q & A: that explains something more. http://social.answers.microsoft.com/Forums/en-US/msestart/thread/5309cb8d-02e1-40e8-974f-0dcedb9ab9fd Kind Regards DFTIM me - TWiTTer: @DFTER