After installing System Mechanic Professional, System Shield is not detected as an antivirus solution by Windows 7 Action Center.
This issue may occur if you have removed a prior antivirus product as part of the System Mechanic Professional installation process.
In actuality, what is occurring is a delayed detection of System Shield by Windows 7 Action Center. Waiting a few moments should resolve this issue without need to take further action.
Note: The speed of your computer can affect the amount of time it takes for Action Center to detect System Shield.