Configure the file association for unknown file types

Windows XP introduced a new features for configuring the file association for unknown file types. When trying to open a file which Windows doesn’t recognize, then it will present you with two options:

  • Use the Web service to find the appropriate program
  • Select the program from a list

The Web service redirects one to ex., which presents different options for opening the file. One might get annoyed by this extra dialog, and it is possible to disable it.

[HKEY_CURRENT_USER \Software \Microsoft \Windows \CurrentVersion \Explorer]
InternetOpenWith = 0

[HKEY_LOCAL_MACHINE \Software \Microsoft \Windows \CurrentVersion \Policies \System]
NoInternetOpenWith = 1

More Info MS Technet: File Association Web Service