Mswmm file: error message appeared

Hi there!
I need someone to find a solution for me. While opening an mswmm file, an error message appeared on my screen as follows:
"….mswmm was created by a version of windows movie maker that is not supported …" I thought about it and first uninstall the software Movie Maker 2.6 and Microsoft’s latest version of MM 2.2 (not sure though!!), but still had the same results like the previous case.
Again I tried several old files of Movie Maker 2.6 I had and came up with the same error message. I am not understating what is going on? Is there any way to edit my files?
Any solutions please?
Thanks in advance.
