Yesterday my pc get freeze so usually I press Alt+Ctrl+Delete to open task manager but surprisingly instead of opening my task manager a message prompt "Sorry Task Manager Disabled". After that I got to my disk drives I show a file named system.exe and I remember very well that I didn't put that file there. When I delete that file it appears automatically after couple of seconds and this file is present in every partition of my hard drive. I scan my computer with my escan antivirus but It is unable to detect virus may be lake of updated virus database. So my question is how can I remove virus from my computer???