Ghis is right, its adware.
Gain or Gator or one of those types.
Spybot Search & Destroy is the most common
http://download.com.com/3000-8022-10194058.html?tag=lst-0-4
Actually, it sounds like she is talking about the windows messenger popups. Which cannot be cleae with spyware removal tools. Though I can't say for sure. Either way, I agree, she should download Spybot.
BUT, if they are messenger spams, she should also go into start-> settings->control panel->administrative tools->services (or just start, settings, control panel, services if not win2K) and set the "messenger" service to "disabled".
That will make them go away.