Quicktime 7 help!

Just exported an Avid movie on a Mac to Quicktime 7.

Took the Quicktime file to Windows XP PC with Quicktime 7 and the file won’t play.

I get: Error 2048: The File is not a movie file.

Can someone help?

Open the file in QuickTime on your Mac. Click Movie, get Movie Properties. On the left select video, and on the right select format. What does it say on the data format line?