Pop Up Blocker in Internet Explorer:
To disable this, click on tools and then internet options and then select security. Now click on customer level. This will bring up a list of options, scroll approximately ¾ of the way down and you will see the pop up option. Set this to enable

Pop Up Blocker in your Firewall/Internet Security:
Depending on which product you have installed, you will need to go into that piece of software and using the 'Help' section locate where the pop up blocker is (it is usually contained within the adverts section, but if in doubt use the help section). Once you have located it, you can set it to allow Pop Ups. Most internet security products also allow you to choose to allow pop ups from selected sites.

Pop Up Blocker in Mozilla Firefox browser:
If Firefox blocks a pop up, it will display a line of text towards the top of the browser, informing you that it has been blocked. Towards the right hand side you will see an options button . click on this. You will then be able to choose whether to allow pop ups for this site, or given the option to re configure your pop up blocker.

Pop Up Blockers in add on tool bars:
Products like Google and Yahoo offer a download which will add a search bar to the top of your browser. These often contain a pop up blocking facility. Most tool bars will have the facility set to block as a default. Most will warn you when they have blocked a pop up or your cursor may momentarily change. To disable the blocker, you will need to click on either options or setting on the tool bar, where you will be able to configure it to allow pop ups.