OK, this is crazy. I went into the settings and turned off "self defense," and then I was able to stop it in the Task Manager. I tried earlier to run aswclear in safe mode, but aswclear vanishes in safe mode and is not visible on the desktop or using windows explorer. I will try again. Avast is not showing in my programs list, All Programs or in Revo Uninstaller. I will boot into safe mode now and try and get back to you.