At the meeting on April 15th I mentioned some software that could be used to open up xml files instead of using IE for those people who don't have one of the full versions of Visual Studio 2010.
This is called Visual Studio 2010 Express and can be found here: http://www.microsoft.com/express/Web/
I've not used this version myself as I have Visual Studio 2010 Ultimate, but I would hope that it would open up xml files in the same manner, also highlighting any errors in the schema or data within each field. Please remember that this is an express version so will not have all of the features.
Regards
Gary