The right click menu. What is it called and how do I acces it?

I have a neat little program that will give you the type of video and audio format of a particular movie  or avi file. I usually access it by choosing a file and right clicking it. The program starts and I get my answer. Now for some reason when i right click a video file the program won't start but rather gives me the "open with" window so I can choose a program. This is not what I want but rather when I right click the line that says "Browse with AVIcodec" that the AVI codec program should start. the program does start and works if I start it up and drag the file into it. Ok so my question is: what is the right click mouse menu called and where can I find the information so I can modify to have "Browse with AVI codec" start up the proper program? i tried uninstalling and reinstalling the program and the program itself works fine. It is just when I right click the menu command to associate with the file does the error occur.