As Chris says in his article, the Windows XP SP2 Security Center tray icon is one of the most annoying things there is, but in Vista I personally find this plain irritating, especially when you don’t want Defender running because it really munches RAM. So here’s how you remove the Security Center icon from your system tray. Sorry it’s long winded, but stick with it… it pays off.

This could well lower the security of your computer. The Security Center is a central and integral part of your computers security, and disabling it will stop all alerts and notifications.

1. Go to Start , select Run (or press the Windows key + R) and type in cmd then hit OK.
2. Type in at the prompt cd c:\windows\system32 then press the Enter key.
3. From there, type in:
           takeown /f wscapi.dll then press Enter.
           takeown /f wscsvc.dll then press Enter.
           takeown /f wscui.cpl then press Enter.
   exit then press Enter.
4. Now you need to make sure that every user has ownership of the files so that every user can “control” them. Navigate your way to C:\Windows\System32 and right click on each file, click on the Security tab and add an entry as “everyone” then tick all the boxes in the Allow column. Apply then OK.
5. Go into services.msc from the Run command and disable the Security Center if you haven’t done so already.
6. The files that you modified ownership from earlier, wscapi.dll, wscsvc.dll and wscui.cpl, change the file extension to .bak.
7. Back into the Command Prompt (Run command then cmd then hit OK) and type in:
   REG DELETE HKLM\SYSTEM\CURRENTCONTROLSET\SERVICES\WSCSVC /F then press Enter.
   shutdown /r then Press Enter.

Once the machine has restarted, you should notice that the Security Center icon and messages would have disappeared.

Big thanks to Chris123NT for this. He maintains a very popular blog on his website, as well as many tips and hints for Windows Vista users. Check his blog out here.

Update for Vista RC2
There’s now an even easier way, hurrah! Open up the Security Center, and in the left hand pane click “Change the way Security Center alerts me”. Click on an appropriate button which suits your needs - the best option to remove it entirely from the notification tray, is to click “Don’t notify me and don’t display the icon (not recommended)”.