How do I cut an AVI file with an unknown codec?

[Olga Krovyakova]

Hello Daniel,

Thank  you for contacting  us.

Please  send  us  the screenshot from AVIcodecs program (here or  to support@solveigmm.com).
Sorry for delayed answer, we have state vacancy till 11 January. 

The required codec is highlighted in green square on the screenshot below:

[daniel]

Some of my AVI files work fine, others can't be opened with programs like "SolveigMM AVI Trimmer" or "VirtualDub", that are made to cut and edit videos.

When I analyze the files (with "AVIcodecs"), it says the video codecs are "unknown". What can I do?