Unwanted Icon in System Tray

I believe there is a type of spyware sitting in my System Tray. It is an
icon that changes from a blue circle with a yellow "X" to a yellow question
mark. When I click on it, it takes me to the following website:
www.virusburst.com.

In the attempt to remove this icon, I have done the following:
- Anti-virus/Anti-spyware scan conducted with ZoneAlarm Security Suite.
- Scan conducted with A-Squared (Free) EMSI Software.
- Scan conducted with Ad Aware SE Personal.
- Scan condcuted with Windows Defender (Beta 2).
NOTE: Scans did not remove the icon.

I have also verified that the Start Up folder. The folder did not show any
"unusual" programs.

I fear that the program is hidden some where in the Registry (or some where
else deeper in my system).

Any assistance you can provide on how to remove this icon/software from my
system will be helpful. Thank you in advance!