Here are the steps to create a Menu Item that opens in a new window:

Create a new Page
At the bottom of the Page Settings choose Url (A link to an External Website) option at the bottom of the page.

Then put the following script in for the Url (using your own url of course).

java script:void(window.open('http://www. ExternalSite.com'));

I found that the easy way:

http://www. ExternalSite.com" target="_blank

..is also working.

I tried both methods and neither worked for me. When I click on the menu item, it just stays on the same tab. It doesn't even reload. I'm using DNN 4.8.4. Has something in the core changed to disable this? Or is there a setting I need to change? Thanks for your help. I would enjoy this working.