When you install XP SP2, Pop-up Blocker is turned on in Internet Explorer and set to the medium setting, which means it will block most automatic pop-ups. The default settings for the pop-up blocker allow you to see pop-ups that are opened when you click a link or button on a Web site. Pop-up Blocker will also play a sound and show the Information Bar when a pop-up is blocked. You can adjust these settings so that Pop-up Blocker works the way you want it to. You can add websites where you want to always allow pop-ups. To export the whole Pop-up blocker setting (including the websites list etc), try this:
Open Registry Editor (REGEDIT.EXE) and navigate to the following key
[HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\New Windows]
Right-click the key and choose Export and save as popup.reg. Now, you can copy the REG file to other systems and merge the contents to the registry. The sub-key named Allow holds the list of websites wherein the Pop-ups are allowed (configured via the user interface)
Example:
[HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\New Windows\Allow]
"www.google.com"=hex:
XP SP2 Pop-up manager registry values and description
Windows XP Service Pack 2: Block Pop-up Windows with Internet Explorer
