Associate a File Type with a Merge Tool
The diff/merge tool included in Team Foundation opens when the user tries to compare two files (or two versions of a file), or when the user elects to perform a manual merge of a file that has conflicting changes.
The tool is compatible with text and XML based files; however, should you want to associate a specific file type with a third-party merging or diff tool, use the procedure that is described in the following procedure.
To perform this procedure, you must be a member of the Administrators or Users security group on the computer where Visual Studio is installed. For more information, see Team Foundation Server Permissions.
To associate a file type with a third-party merge tool
From the Tools menu, click Options.
In the Options dialog box, open Source Control, expand it, and then click Visual Studio Team Foundation Server.
Click Configure User Tools.
In the Configure User Tools dialog box, click Add.
In Configure Tools dialog box, specify the extension you want to associate with your tool in the Extension box, for example .cpp or * for all files.
Use the Operation drop-down list to click Merge.
In the Command text box, either type the path and name of the tool tool, or use the ellipses to browse to it.
In the Arguments text box, type any arguments that your tool requires.
The arrow button shows a list of available variables that the diff/resolve command will fill in before passing them to the configured tool as specified in the arguments box. Any other text in the argument box will be passed to the tool directly.
Repeat steps 4 - 9 to add more file type extensions.