I actually had a heck of a time with viewing sonar files mostly because the people at Hummingbird didn't correctly inform me how to load and use it. I mean the Son2xtf converter. It took probably a month dealing with them till one person told me to use the Humviewer. Sorry It was not a new program just poor spelling on my part. But the Humviewer is fantastic compared to the Son2xtf program. No comparison. Anyway it got down to a administrator to give me her email to deal with to find out all I had to do was open the viewer first them load the file to look at it. I was really dis sappointed with not being able to look at files and it was so simple. They told me it was a issue with windows 7 so I went looking in the wrong direction. Thanks for inquiring and re posting. I am a newbie so to speak and its good people here really watch and are so helpful. Thank you, Hollywood