Sometimes the default program associations in Windows might be broken. Malware or spyware program that redirects certain file types to their software or webpage, viruses that confuse users by altering extensions or their associations, or just simple broken registry caused by uninstalling poorly written software.
When Windows is freshly installed, the most basics file types like AVI, JPG, GIF etc., or even some special Windows files, are by default associated with certain program like Windows Media Player for AVI. Whilst some associations are naturally changed for better programs, like when you install your favorite media player and make it so AVI is launched via it, some associations are better when they are in their default state.
We have made a cache of registry files, that you can use to restore the default, clean Windows install, association of most common file types. Just download the ZIP, extract the registry file you need and import it to your registry to apply the information contained within.
Example: Fixing broken CPL association in Windows.
Let's say the default association for your CPL files - Windows control panel is broken. Simply find the corresponding CPL registry file from the downloaded ZIP file and merge it to Windows Registry. That should fix the problem, and your *.cpl files should once again directly open the control panel.
This method and registry entries should work in Windows Vista, Windows 7, and Windows 8.
You will of course need administrative rights to import registry entries to Windows registry.