I found a fix for this problem via another forum. Here's the info - I hope it helps someone else...
(derived from the instructions on: http://filext.com/faq/broken_exe_association.php):
Go to My Computer, then Local Disk (C:). In the top left menu:
*Click on Tools.
*Click on Folder Options.
*Click on the File Types tab.
*Scroll down to where EXE would be in the alphabetical order and make certain EXE is NOT there (if it is, edit it by changing the association shown there to Application).
*Select the NEW button.
*Type in EXE for the extension and select the Advanced button.
*From the list, select Application.
*Look for a Restore button. If it's available, click on that (the Restore button only shows up when there is a problem on the system).
If this procedure doesn't fix your machine, there are other fixes shown on the link above.