Symantec is dragging its feet about allowing its programs to communicate with the new Windows Security Center – resulting in the balloon in the lower right corner of the screen that says your computer “might be at risk.” I don’t know why Symantec is alarming you instead of solving this problem. It’s frustrating.
If you want to disable the “at risk” messages, click on Start / Control Panel / Security Center / Virus Protection / Recommendations. Check the box that says, “I have an antivirus program that I’ll monitor myself.”