Pop-up blockers prevent unwanted web pages from appearing on your screen while browsing the internet. However, sometimes necessary pop-ups are blocked by the system. The pop-up blocker can be disabled for certain sites. This article gives instructions on how to turn on/off the Pop-up Blocker and how to allow pop-ups on specific websites for multiple browsers.
Managing Pop-ups in Windows
Managing Pop-ups in Mac OS
Managing Pop-ups in Firefox for Mac