Windows 7 incorporates a mode that allows you to run programs written for earlier versions of Windows. Some old programs may run poorly or cease to run on Windows 7. When this happens you can find a solution by invoking the Program Compatibility troubleshooter.
Windows Task Manager allows users to start and stop programs, view programs running on their computers which include system services, identify executable names of programs, and change the priority of the process in which programs run. In the hands of the wrong users these useful features can do more harm than good.
If somehow the default program associated with a file gets corrupted or changed to another program then any files that belong to that program would not run! Apart from problems with .exe file extensions you can use the registry editor to undo any other incorrect file associations. In cases of .exe file association problems you can read a previous article titled Filename extensions – Can’t open .exe files? since, using the procedure below would not allow you to open the registry editor to resolve .exe file association issues!
To determine which applications in Windows 7 are responsible for activity on your hard disk, including which files and folders are being accessed you can use either Process Explorer or Resource Monitor. Although, Windows 7 offers an enhanced version of the Resource Monitor tool, Process Explorer is not part of the native operating system and you need to download it from Microsoft’s TechNet. Process Explorer allows you to determine information related to running programs such as, which program has a particular file or directory open or handles opened and DLLs loaded.
In Windows when you try to open a file with an unknown extension (which Windows does not recognise), a prompt is displayed asking you if you want to use the web to search for the appropriate program that can open the file. As many users including myself, rarely use this web service and opt to select a program from the system, it is more appropriate to eliminate unnecessary steps like a never-used prompt. To remove the prompt you need to add a registry value called InternetOpenWith.