You should be able to open Internet Explorer using either of these methods:

• the blue "e" program icon

• in the Start menu search box, paste the following and press Enter:
  
  iexplore
  
  (you'll see Internet Explorer come up as a match on the top part of the Start menu search results panel)

If the Start menu search method works but not the taskbar icon, the taskbar icon might be broken in some way. Try removing it (right-click > unpin) and creating a new one by finding Internet Explorer on the Start menu, right-clicking it, and choosing Pin to Taskbar. Does a new shortcut work any better?

Thanks for the suggestion. Unfortunately, it didn't work. I have tried going to my programs list, where internet Explorer appears, with same result: a Mozilla window with the "This page can't be displayed" message. I am using Windows 7 Pro. I think somehow Mozilla is taking over my attempts to use any other browser. If so, how do I prevent this?

Could you try using the Internet Options Control Panel to make Internet explorer your default browser again and see whether that makes any difference?

http://windows.microsoft.com/en-us/internet-explorer/make-ie-default-browser

If that doesn't help, your Windows system files might be damaged. You could try using the System File Checker as described in this article:

https://support.microsoft.com/en-us/kb/929833

Otherwise... I don't get it. I assume other programs start normally and don't try to open in a browser.

As you were making your suggestions, I had the idea to go to the internet settings feature. In the Internet Properties panel, I went to the Advanced tab and clicked on the Resets Internet Explorer 's settings to their default condition. It Worked! I also have Mozilla Firefox as my default browser. Thanks again.

That's great news, thanks for reporting back. You can mark your last reply as the solution in case this afflicts anyone else. https://support.mozilla.org/questions/1115575#answer-859700

I replied too soon! It turned out that only the banner of the browser window had changed. I still cannot open the internet Explorer browser. I tried the System File Checker as suggested. There were no damaged Windows files. Thus, I am still where I was at the beginning: I can't open the internet Explorer window, even if I've designated it as my default browser.

If you go into the Windows Favorites folder and click a favorite, does it launch in IE?

After some searching, I found the Windows Favorites folder. There does not appear to be much there. When I clicked on the IE icon, I got the same window as before: a Mozilla window with the "This page can not be displayed message".

Usually there would be one or more Internet Shortcuts (.url files) in the Favorites folder and they definitely should open in your default browser.

What if you paste a URL in the Start menu search box and press Enter to load it? For example:

https://www.bing.com/

If that doesn't open in the default browser, something is very broken, but I really don't know what it is.

The bing search engine loaded when I typed the path you recommended in the Start menu search box. However, I still can't figure out how to open IE.

If the URL opened in IE, it means Windows understands IE to be your default browser. Success! You can save a shortcut to your desktop as a future way to start up on Bing in IE. Or save another page, whatever you like.

But I don't know what's wrong with your regular IE shortcut. Perhaps that is best addressed on a Windows forum, either Microsoft's own site or another Windows site such as http://windowssecrets.com/forums/.

As you may recall, since I can't open IE successfully, I used the URL and loaded the bing search engine from my default browser - Mozilla Firefox, As I have gone through several attempts to open IE, including trying to make it my default browser, I am still at an impasse. I always get Mozilla opening a window with the "This page can not be displayed" message.

Oh, I thought you used Internet Options to change your default to IE. I realize now you skipped that and did an IE Refresh.

Please try making IE your default browser:

http://windows.microsoft.com/en-us/internet-explorer/make-ie-default-browser

Then test the URL-in-the-search-box method again as a way to launch IE.

Well, I am now able to open Internet Explorer, but only by typing the URL in the Search box. I've tried pinning the IE icon to the taskbar without success. I've tried various procedures using the Microsoft help section as well as the IE default browser suggested in the above panel. Thanks for your help. At least I can get to this browser now!!