The WebBrowser control loads properly any mht file if I use the Navigate method, but when I use the DocumentText or DocumentStream properties, the source of the mht file is displayed as if I opened the file in notepad. If I write the stream to a temp file then Navigate to it, it works properly, but I don't want to do it this way. This issue seems common, but I didn't find a working solution for it. Some people suggest I should fool IE by implementing IPersistMoniker com interface, ...etc. I have tried with this a little bit, but unfortunately I got the same result. May be I have done something wrong. I still feel their should be a more straightforward solution (other than saving in a temp file first), any idea?