Hi,
Thank you for choosing Windows RT.
It looks you are unable to open or edit .xfdl files on Windows RT. We will work together and try to resolve the issue.
An XFDL file is a data file primarily used by businesses to store business transactions and other legally binding transactions. The XFDL format is based off of XML, a similar format used make documents more accessible for
HTML. XFDL files are supported by Windows Notepad, the built-in basic text editor for all Windows operating systems.
You may launch Notepad and open the file to check.
a. Launch
start screen and search for Notepad.
b. Click on ‘file’ tab and open the
xfdl file from the downloaded location.
You can also search for third party programs to open. XFDL file using your favorite search engine.
Note: Using Third Party Software, including hardware drivers can cause serious problems that may prevent your computer from booting properly. Microsoft cannot guarantee that any problems
resulting from the use of Third Party Software can be solved. Using Third Party Software is at your own risk.
Hope this helps. Let us know if you need further assistance with Windows related issues. We will be happy to help.