Unassoc

Unassoc is a free program that allows you to disassociate certain formats from certain programs on Windows Vista and Windows 7. You probably know that with the standard tools of these operating systems you can, for example, make video in MKV format open in the right multimedia player, and TXT documents in your favorite text editor. However, Microsoft has not provided any GUI tool for canceling such format bindings to certain programs. You can only "re-associate" the format with another program. But the cancellation can be done with this small utility by Ramesh Srinivasan of Winhelponline.

The Unassoc interface consists of one small window, and the program does not even need to be installed in the system. Just extract the ZIP archive and run the executable file with administrator rights. So, what do you need to do to undo the association of a certain format with a certain program? Simply enter the required extension (or select it from the list) in the "File types" field and press the "Remove file association (User)" button. This removes the user-specific association made through the Open With dialog, and Windows then uses the global association settings for that type. The changes are applied instantly.

The program automatically generates a list of registered file extensions. After making changes, you can update the list by pressing the "Refresh list" button. There is also a "Delete file type" button, which deletes the chosen file type from the registry completely, removing both the user-specific and the global associations, so it should be used with care. Apart from the About and Visit Homepage buttons, that is all of the significant interface elements Unassoc has. The developer tried to make the program as simple and understandable as possible. The last version, 1.4, was released in 2009.

Unassoc allows users to easily remove file association with certain applications on Windows Vista and Windows 7.