nitesh, google and bing don't do it... any browser that defaults to google or bing or the hewlett packard home page or whatever come pre-packaged with that site as it's home page... the only way to change this, is manually, either by:
1) high-lighting the address in the address bar and dragging it to the little "home" icon
2) going to the browser's settings and pasting or typing the address
3) installing software package such as yahoo messenger or the like, that changes these settings for you when you agree during the installation process, usually by checking a box and clicking agree