Orion 99,
With AVI files, a lot may depend on what version of EMC 9 you have.
If you have the full retail version then you should be able to deal with any AVI files that you have the proper 'codecs' for, however if you have the cut-down DELL version [9 DE] then you will likely find that your software won't handle AVIs which use the most popular DivX and XivD video codecs, or the most popular AC3 audio codec.
There's a detailed discussion on the cut-down versions
HERE which explains that.
A good way to investigate what 'codecs' your AVI files use is the GSpot Codec Information Appliance which can be downloaded free from
here. You run GSpot and drag your AVI file onto the GSpot display screen. It will analyze the AVI, and tell you what codecs were used, and if you have the necessary ones installed.
Roxio may deal with Matroska [MKV] stuff in later versions, but version 9 is getting on for three years old, and I'm pretty sure it won't even look at MKV - neither would your Windows MP if you were using a 3-year-old version.
Regards,
Brendon