Spokavriel and epmiali write:
Your Default Browser is the one that your system will automatically open when you click on a link outside of an open web page.
Anyone remember how to change which is your default after you have told the system to stop with the popups that keep asking you to make the other browsers default?

Change Default Browser within Windows
• Windows XP:
o Go to START, then click “Set Program Access and Defaults”. Then select custom and select the browser you would like to use as the default and click ok. (You can also find “Set Program Access and Defaults” by going to the control panel and selecting Add/Remove programs).
Change Default Browser within Browser

     ●     Internet Explorer: 
                    ◊ Open Internet Explorer and go to Tools -→Options -→Programs. Check
                       the box that says “Internet Explorer should check to see if it is the
                       default browser.” Restart Internet Explorer. It should ask if you want to 
                       make Internet Explorer the default browser.      
     ●     Mozilla Firefox: 
                   ◊ Open Firefox and go to Tools -→Options -→General. Click the “Check
                      Now” button in the default browser section. If Firefox is not the current 
                      browser it will ask you if you want to make it the default, otherwise it 
                      will let you know that it is already the default browser.
     ●     Opera: 
                  ◊ Open Opera and go to Tools -→Preferences -→Default Application. 
                     Put a check  in the box next to the dialogue on the bottom  of the window
                     asking whether you you want to “ Check if Opera is default browser on 
                     startup.

It should also be noted that on an OS X (mac) you change your default browser by opening Safari, clicking the Safari menu, click preferences. Under the General tab you have an option to select your default browser.

That’s great for XP, but is it different if you have an Earlier Windows?

William writes: For users of other versions of Windows, you can use the method of setting the default browser from within the browser, as shown above. Alternatviely, using Windows Update will download and install the “Set Program Access and Defaults” program to your computer, regardless of its version.

Edited/Updated By: DanVersion1 01/10/04