When you select programs from the Start menu or shortcuts nothing happens, the "Open with" dialog box is displayed or a specific program runs. The .lnk association is either missing, incorrect or corrupted. Because all shortcuts and Program Menu items are files with a .lnk extension, selecting one either brings up the "Open with" dialog box, a specific application such as Notepad.exe or Wordpad.exe or doesn't do anything. You can correct this by either restoring the registry key from another working computer or manually replacing the registry key. See : Q172053