Popups are the scourge of the internet made worst since advertising revenue plummeted 90% in 6 months between 1999 & 2000.
Windows XP came with 'Messenger' not to be confused with MSN messenger. This was no problem at 1st but as more advertisers pay for 'Messenger' popups they have become a nightmare for XP users.
There is the cure for Messenger popups within XP. Open the Control Panel from the Start menu. In Category mode click on Performance then Maintenance. Click on Administrative Tools then double click Services. Scroll down the right hand list & double click the Messenger entry. Click the Stop button & select Disable from the Startup menu. Click OK to apply. You should no longer be bothered with these popups
You can see under my signature what I do on the 'net Noely.
The program has a subscription service for those who want to stop the adverts & popups that pay for the free service. So many complained they got popups after paying to stop them that we now pass those instructions to them. They originally blame the program but it's microsnot that causes them.
You could try having a look at Steve Gibson's website - www.grc.com - he's spent much of his career looking for the flaws in Windows software and producing patches for them - lots of info there about the more sinister side of 'open ports' and other 'features' that ship with new software