Using Pega Robotics to compare two XML files is possible, but you're really just writing C# code to do it, and thus not really using anything specific to Pega Robotics. I would use a C# script where you pass it the path to each of the files. What type of comparison and output do you want? If you just want to know if they are different, then you could use a combination of the FileUtils and a StringUtils components to answer that. FileUtils to read the file to text and a StringUtils to compare the two.