Lets double-check that Firefox installed properly: Please go to [http://www.getfirefox.com www.getfirefox.com], and download a fresh version of Firefox. I'm assuming you are using Internet Explorer to download Firefox. Instead of hitting Run, let's try hitting save. Remember where it saves the installer file on your computer. After the download has finished, double-click and run the Firefox install. Once it is finished, try to start Firefox up. Let me know how it goes! You should have an icon on your desktop, or if you go to your Start Button, then all Programs, Mozilla Firefox will be listed in there.