For solid ad protection nothing beats ColdStop Popup Killer.
License: Shareware
OS Support: WinXP, Win2003, Win Vista

OverApps is the free browser add-on that lets you replace ads with apps like: Facebook, Twitter, TMZ, ESPN, Flickr, Chuck Norris, PandaCam, CNN & moreDownload OverApps for free now and have the web the way you want it.
License: Freeware
OS Support: WinXP, Win Vista

Adblock IE is an adblock addon for Microsoft Internet Explorer With Adblock IE, all advertisement will be removed automatically from the websites you browse, and it allows you to enjoy the web without annoying ads!.
License: Shareware
OS Support: WinXP, Win Vista

Less is more! With Adlesse less ads mean more space for useful widgets! Substitute all the annoying banner ads for news blocks, your friends` tweets, Facebook feed, weather forecast, interesting facts, famous quotes and more All browsers supported.
License: Freeware
OS Support: WinXP, WinNT 4.x, WinNT 3.x, WinME, Win2003, Win2000, Win Vista, Win98

Adguard is a powerful ad and popup blocking utility It is compatible with all popular browsers and protects you against obtrusive and unpleasant advertisements, speeds up page loading and reduces bandwidth usage.
License: Shareware
OS Support: WinXP, WinNT 4.x, WinNT 3.x, WinME, Win2003, Win2000, Win Vista, Win98, Win95, Win 3.1x