Bing Desktop won't install anymore...

I am running Windows 7 on my HP pavilion laptop and had 'Bing Desktop' installed for last 4 years but all of a sudden, 5 weeks ago, the program malfunctioned and when I tried to install a fresh file, it showed an error saying, "This file does not have a program associated with it for performing this action. Please install a program or, if one is already installed, create an association in the Default Programs control panel." Could somebody let me know what this means and how to do it? I miss 'Bing Desktop' and its themes very much!!
I will be most grateful for assistance...
Thank you!