I want to know who (Windows username)created and who have modified a particular qlikview file. I have checked the xml files created from the qvw file using the -prj method, but there is nothing related to that. There is also a file with .dat extension which might have storing this information. Can anyone help me in reading that dat file.
A better way of doing this in the future is to implement a source control system, you are out of luck with Qlikview as it does not capture this information.
The author and/or last changed user name is not part of the default metadata inserted into the document. So unless something similar to the suggestions above was already in the document, there will be no way of determining who was responsible.
A better place to look is your windows environment and see if the information is held in a back-up.