Is the most powerful video convert software. It is an all-powerful tool for users who want to put DVD movies and videos or audios on their players. This omnipotent video converter can both Rip DVD and Convert Video, Audio to AVI, MPEG, MKV, WMV, FLV, MOV, MP4, 3GP, 3GPP, MPG, ASF, VOB, WMA, M4A, MP3, etc.
It supports all common portable players such as iPod, iPhone 3GS, PSP, Zune, Archos, Creative Zen, Walkman, BlackBerry, Palm Pro, Gphone, Cell phone, etc.

In the following guide I will show you how to convert M2TS to MPEG with the converter.

It also provides you with a series of video editing functions, such as video cropping, movie trimming and video effect adjustment. It enables you to preview video with two real-time preview windows out of your movies in an intuitive way.
certainly,
answers.yahoo.com will offer you more options
I hope this may help you.

Some players need codec to support playing M2TS video, but some do not even play it at all. For PC users, converting M2TS to WMV sounds a good idea, as you can get videos with relatively good quality and play them with most players.

If you are looking for free video converter, this website will help you a lot. It collects 18 free online converters, no need to download anything, they are totally free without any limitation and watermark. My friends recommend it to me, it's pretty cool. I'm sure you will fine one to convert video to your zune player.
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Hope it helps. Email me if you need further help.
Hi, I recommend Cucusoft Zune Video Converter which can convert almost any video format to play on Microsoft Zune Video Player, e.g. DivX, XviD, MOV, RM, rmvb, MPEG, WMV, AVI to Zune Movie / Zune Video format.

In the following guide I will show you how to convert M2TS to MKV with the converter.

Hope it helps!
you can have a try Aiseesoft Total Video Converter
it can help you convert any videos to the format you want
zune support WMV and MP4
but this tool is not free
hope it helps~