.java files opening in IE

[gehang]

I use textpad to write java files for my programming class. I email the files to my teacher. When my teacher clicks them to open the attachment they open in Internet Explorer.

My first thought was to blame the teacher (maybe his extension preferences were messed up) but he insisted my files were the only student that happens with. So I did a test. I created two java files. One in notepad and one in textpad and emailed them both to him.

I then on his computer, double clicked each one and sure enough one opens in notepad, and the textpad one, opens in IE.
I can't for the life of me figure out why though..

Both are saved as .java files. (ansi pc), and his computer peferences are set to open .java files in notepad. (he doesn't have textpad).

I checked in the command prompt view to make sure the filenames were correct and not filename.txt.java or something crazy. It says test.java and test2.java respectively.

I don't get how two files both ansi pc, with the same extention, could be seen as different files by windows.

Anyone have any advice?