I've just loaded Dreamweaver on a new Dell Precision M60. Had much success with embedding windows media clips on my old Dell Latitude, so know my code/parameters, etc. are correct. The videos will play on my new machine but NOT when I embed them in Dreamweaver: when I preview in browser Windows Media Player comes up but controls are grayed out and video does not play. File is there and working. Any ideas?

Sounds to me like maybe your computer can't find the video file.

Is it possible that on your old computer there was a local copy that your computer looked at - and on the new one there is either not a local copy or it's in a different location.