But a couple versions back, "tabs" came into being.  Tabs are quicker and easier and use less resources as they are not a completely new and separate instance of the program running, but simply another screen run by the first window you opened.  The screen is called a tab. 

BUT--you can open another, different page in your forum in that tab.  Or you can open a completely different web site in that tab.  And it only requires one browser instance to to run all these tabs, not a separate browser instance for every page.

In Internet Explorer:

To open a tab you can click on FILE/NEW TAB in menu bar at the top of your screen if the menu bar is shown--it's not default in current versions of IE.  Or, more simply, notice that there is a small square attached at the right of the title of your forum at top of the screen.  Not the address bar but the rectangular title jut right of it.  If you click on the square attached to that rectangle, it will open a new tab.

Once you open a new tab you'll see a blank page, and the address bar will be available to type in a new URL.

OR EVEN MORE SIMPLE TO DO, from your current page, right click on the other page you want to view, and click ON open in new tab, AND voilà, A NEW TAB WILL OPEN.

To open a tab in a different web site, click on your favorites, find the address, right click, and choose OPEN IN NEW TAB.