First, it would sure help if we knew more about your computer. Which operating system? Which browser are you having this problem with? And if Internet Explorer, please give the version number..The more information you give us, the better informed our answer will be.
In the meantime, the link below should explain how to fix the issue:
Can?t Open a New Window In Internet Explorer
Hope this helps.
i think that i might have moved somthing in the internet options because i put "open new window" and i get a new screen but in the same window. no matter what i click on, i can only have 1 window while im online. i want to have more than one window open, what do i do?