Your computer might be infected with a virus, a Trojan horse or with some ad ware.

A computer virus is a software program that has been intentionally created to cause a user grief, spread to other computers, or destroy data on an individual's computer.

A Trojan horse is a type of program that is often confused with viruses. This is not a virus, but simply a program (often harmful) that pretends to be something else.

To check and clean your computer install these programs:

AVG Free Antivirus

Ad-Aware SE Personal

Another way to get around this problem is to install Mozilla Firefox 2.0 web browser. Mozilla Firefox is a fast, full-featured Web browser that makes browsing more efficient than ever before. Firefox includes pop-up blocking; a tab-browsing; integrated Google searching; simplified privacy controls that let you cover your tracks more effectively; a streamlined browser window that shows you more of the page than any other browser; and a number of additional features that work with you to help you get the most out of your time online.

Version 2 features an updated theme and user interface, built-in phishing protection, enhanced search capabilities, improved tabbed browsing, and inline spell checking.