I have an HP computer with Vista Home Premium software. I have Internet Explorer which I seldom use; and I also have Firefox which I use constantly. My computer frequently stops and a dialog box appears on a blue screen, that says: "Preparing security options", lists about 5 choices, one of which states that my computer is LOCKED. I press Cancel and eventually it goes back to the page I was browsing. When signing off (below the Start menu), there is a padlock icon.....when I click on it, it WILL NOT unlock the padlock. I am stymied. Any solutions out there? I need help please. TIA Voyager234