Is there any free software that will help me prevent unwanted advertisements and unwanted images from loading automatically... for example many websites offer free email like Rediffmail or Yahoo, but also one cannot stop the advertisements that come bundled with the free offer.

I want these to be stopped automatically and only me email account be visible.

What sort of ads are you talking about? I have a Yahoo email account and I've never had a problem with any sort of ads loading. Are you getting pop ups?

Are you using IE or Firefox?