If it's a square taskbar icon try the following:
Double-click (or right-click) and open SecurityCenter
Click Advanced Menu (bottom left)
Click Configure (left)
Click Computer & Files (top left)
You can disable virus protection on the right and tell it for how long.
If it's a shield-shaped icon double-click or right click to open SecurityCenter
Click Virus and Spyware Protection
Click Real Time Protection and switch it off and tell it for how long.