How to completely stop notify icon, not just disable.

Hello. I am trying to stop the Windows Security Alerts Taskbar notification icon from showing. I disabled Security Center and Security Accounts Manager in "Services", but the notification icon is still there. I want to kill every un-needed process to free up CPU and memory(as I am optimizing for performance), rather than simply hiding it in taskbar properties menu(which would probably still have it running).
I think I found the registry key:
SVC\HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Security Center\Svc\S-1-5-21-4137006042-56807685-2926720527-1000
Tried to Change Enable notifications to 0, wouldn't let me . Error notice said "Cannot edit, Error writing the values new contents".

Any Ideas? Thanks in advance!

This won't help with performance much (if at all), by the way.

Double click on the icon to bring up the Security Center. On the left, click "Change the way Security Center alerts me", then click the bottom one. Done.

Thank you! Your solution was clear, consise and dead-on!!
I realize were talking about non measurable gains here, but with every service disabled, registry keys optimized and various tweaks, I am trying to barely stay above 30fps in CRYSIS.
Thanks again for sharing your knowledge and time.
Have a great one!!!!!!!

Ah it's Crysis you're trying... in that case, good luck!