If you have a new PC, Internet Explorer probably opens on the manufacturer's Web site. If you haven't changed that already, navigate to the home page you want, click Tools, Internet Options, and in the 'Home page' box on the General tab, click Use Current. Occasionally, IE may open to a Microsoft page to inform you of a critical update. If clicking the Home button returns you to the expected place, everything is fine.

Some programs or Web sites change your home page. (You may find a warning about the change in the fine print of a license agreement.) Follow the procedure above to switch it back; then reboot to confirm that the change has taken effect.

If the unwanted page returns, some piece of scummy software is resetting the home page every time you start Windows. Most evil apps of this type can be cut off by one of two free programs: Ad-aware or Spybot