Most web browsers have a pop-up blocking feature that, when enabled, can help prevent unwanted ads from appearing or potentially installing spyware/adware on your computer.

However, you may occasionally find that you can't view a website such as ARTSTOR (www.artstor.org) that displays non-ad content in pop-up windows because it is blocked by pop-up blocking. If this occurs, disabling the pop-up blocker is required to allow the page to show. Firefox supports adding an exception for the website in question that can allow you to view the desired content while retaining the convenience of the pop-up blocker.

Instructions for disabling pop-up blocker in Internet Explorer can be found at: 

http://windows.microsoft.com/en-us/internet-explorer/ie-security-privacy-settings#ie=ie-11

Instructions for disabling pop-up blocker in Safari can be found at:

http://support.apple.com/kb/PH11946

Instructions for adding an exception in Firefox can be found at:

https://support.mozilla.org/en-US/kb/pop-blocker-settings-exceptions-troubleshooting

Instructions for disabling pop-up blocker in Opera can be found at:

http://www.opera.com/help/tutorials/personalize/content/#popups