In this post presenting a different solution, suitable for those who do not use Internet Explorer as your Web browser instead preferring other browsers (Firefox, Opera?).
Windows Live Messenger displays ads using Internet Explorer: So the idea is to intervene on IE settings to prevent the appearance of ads (especially troublesome dynamic enlarge passandoci above with the mouse pointer), but I can not exclude that with this trick not even be displayed banners static.
You just open Internet Explorer, go to Tools menu-Internet Options Security set to “High” level of protection of the Internet.

Click on Apply and OK and close Internet Explorer.
When this is done, log Windows Live Messenger and riconnettetelo: the ad should see a banner all white, or you get the banner following standards:

(Tested on Windows XP Home Edition SP2 + IE6 + WLM 8.5)



@Jane: You are welcome
Thanks works grate win 7 64 bit, wlm 14.0.8089.726