Cannot select program in File open mode

File default opener error, in the file open mode, there is a "always use this program to open these files" is gray, check box can not be selected.
such as the RP format file established by Axure, the player as a streaming media file, the default associated with the forced open program.
One, right--open method, select the program you want to use to open this file
Second, Folder Options-file association open the Control Panel "-> folder Options, file type, the registered file type, find your file name extension in the list, delete it, and then log off the re-login. Or, "Change" the way the file is opened.
Or, in the file type, folder Options, My Computer "-> tools
The above method is invalid, open "Folder Options"-> Advanced, Pop-up dialog box, you will see an action, the following is an option is open, this is the opening file you selected before the program; If you want to change the open program, click Edit; You can also customize the named Open and then associate to the specified program (. exe)
Iii. Registration Form-file association
File association is the default way to open a file of a type, such as the default state of the text file txt is associated with the Notepad program, we can double-click the text file, it is possible to directly run the Notepad program to edit it. The Association of a file is implemented through the registry.
To enter the HKEY_CLASSES_ROOT of the registry, select. txt, view the right window, double-click Default, and you can see that the. txt corresponding entry is txtfile. Then, under this key, locate the Txtfile key, expand Shell->open->command, and in the right window, double-click Default to see the command to open the. txt file. You can create a file association by adding a few similar items to the command.
Four, the simplest and most rogue method is the System Restore.