For Internet Explorer :    1) In ie tool menu, make sure the popup blocker is turned off; 2) In ie tool menu, select "Internet options", security panel (choose approriate zone), customer level, under "misc", check the box in front of "disable" regarding "use popup blockers";  With Windows XP Service Pack 2 (SP2) Internet Explorer allows you to prevent most pop-up windows from appearing over pages you want to view while you're using the Internet. Using Pop-up Blocker When you install 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. To change Pop-up Blocker settings 1. Open Internet Explorer. 2. On the Tools menu, point to Pop-up Blocker, and then click Pop-up Blocker Settings.   Internet Explorer Tools menu If you want to see pop-up windows from a specific Web site, type the address (or URL) of the site in the Address of Web site to allow box, and then click Add. Pop-up Blocker Settings window Tip To temporarily allow a site to display pop-ups, click the Information Bar when it notifies you that a pop-up has been blocked.         Then click Temporarily Allow Pop-ups.   For Google Toolbar   :

OR   If the Popup Blocker is preventing a new window from opening, you can always let a new window open from a "blocked" site by holding down the CTRL key while you click on a link. For Yahoo Toolbar   :