What you need are codecs:
CODECs list and alternate players for Movies. However, I'm not sure WMP has the ability to burn DVD's. For viewing we normally recommend this player:
VLC - (click on link) _ (choose nearest mirror site) as it has in-built codecs. Can also play vcd's, dvd's, etc. But it is only a player & can't burn.
For burning, I'd suggest looking around the forums. There's many suggestions about alternative software for burning dvd's. Nero & Roxio are usually the best but if you don't have them, others are suggested. You could also try
TMPG which is shareware/trialware. I think you get a limited period of free use for burning.
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