Hi Shmiel,
It depends what pop-up adverts you are getting.
If these are the pop-ups that say 'Messenger Service' in the title bar to
stop these messages you can activate the Windows XP firewall (Microsoft's
recommended way, another firewall program is required if your on AOL) on
your system or disable the messenger service on your computer.
To disable the messenger service go to Start > Run and type Services.msc
You will now be presented with a list of services on your computer, move
down the list until you see 'messenger'. Double click on this, and set
Messengers Startup type to disabled and stop the service if it is running.
If these are website pop up ads run ad aware on your system to remove any
ad/spyware that might be causing ads
http://download.com.com/3000-2144-10186632.html?tag=lst-0-1
Hope that helps
Mark