This used to work. However after a recent Windows Update it is no longer possible neither to use net stop command nor the services applet to stop this service.
It also seems not possible to use either sc config or the services applet for disabling the service.
How this can be resolved?
Open Microsoft Security Essentials and go to the "Settings" tab. Click "Real-time protection" and uncheck "Turn on real-time protection (recommended). Save changes. This should disable the real-time protection service.
Hit the windows key or click the start button, open control panel and "add/remove programs" you should be able to find it either of those along with a option to uninstall/remove it.
