Uninstalling “Microsoft Security Essentials”

Go to the operating system's standard location to remove files, from within the Control Panel (appwiz.cpl, called “Add or Remove Programs” in Windows XP and called “Programs and Features” in Windows Vista). Find “Microsoft Security Essentials”. Right click on the option if needed (e.g. this requirement has been seen in Windows Vista) in order to accomplish the next simple task: Choose “Uninstall”.

Message Notification: Multiple security problems

The next screenshot shows an impact of uninstalling “Microsoft Security Essentials”. The “Windows Defender” service stops working when “Microsoft Security Essentials” is removed.
Message Notification: Windows Defender is out of date.

Microsoft Security Essentials Uninstall completion

The Windows “Security Center” icon, in the Control Panel, may report something different now. If freeing up a bit more disk space is desired, look underneath %Allusersprofile% (which may be “C:\ProgramData”). Specifically then, under Windows XP, look under “.\Application Data\”, and from any supported operating system, then look under the current location for Microsoft. There may be a “Microsoft Antimalware” (which, had a “Definition Updates” folder prior to the uninstall), and there may be a “Microsoft Security Essentials”. They might be about 13MB in there after the software's uninstallation process has completed.

Uninstalling the software may/does uninstall Windows Defender.