Security Center alerts users to protect their computers against a variety of security risks.
The Security icon pops up in the system tray and reminds us regularly about security related vulnerabilities.
For example the anti-virus software has not been updated or the firewall is not configured properly, or the automatic update is not on or not configured properly.

But if one wants to get rid of this icon and constant reminders he/she can do the following:

Click on START > RUN and type regedit
Then click on Ok button.

The Registry Editor, will be appeared.
In the left pane of the Registry Editor, navigate to the following subkey (making double click on each registry key):

HKEY_LOCAL_MACHINE
SOFTWARE
Microsoft
Security Center

Highlight Security Center and you will find the following entries as default (the default value data is zero):

AntiVirusDisableNotify
AntiVirusOverride
FirewallDisableNotify
FirewallOverride
UpdatesDisableNotify

Now right click on each item and select Modify.
Change the Value Data from 0 (read ZERO) to 1 (read ONE).

Close the registry editor and restart the computer.