Trapped scam page
One browser window fills the screen, plays an alarm, claims the computer is infected, or shows a phone number to call.
Safe first move
Do not click the warning or call its number. Close the browser normally; if the mouse is trapped, Microsoft recommends Alt+F4 or a normal restart when the browser will not close.
Boundary
A scary page is not proof that Windows is infected. Do not install its tool, pay it, or type any account information.
