Hi, I've been hearing advertisements when no pop-up or browser windows are open. I'm pretty sure my computer is infected with something that is causing this to happen. I've run several anti-virus programs, including Norton Security Suite, Spybot Search & Destroy, and Malwarebytes, which have each detected and fixed several issues. However, I'm still hearing sounds from the advertisements every few minutes. Please let me know how I can fix this! Your help is greatly appreciated!