Windows 7: Cannot save video in high definition display

I am using Windows Live Movie Maker 2.6 running in Windows 7. I have found that when I try to save my completed movie "For high-definition display" it will not be saved. The saving process stops sometimes at 13%, 27% and even 99%. My computer freezes completely and I have to switch it off and on again manually. However, it will save in "For computer" setting, with no difficulty. I have noticed it only when I try to save MOV video clips. There is no problem when I save WMV video clips. Is this the key to the problem?

How large would the .mov filesize have been if completed?

In one instance, you say completed movie, and in another, you say movie clip.

There may be a filesize limit with respect to .mov.

Giggaggles,
The biggest completed movie I saved in HD is 5.51 GB and runs for 35 minutes. All the video clips comprising that movie are in the WMV format. No trouble at all in saving or viewing it on HD TV.

The movie I have trouble saving in HD is 206 MG and runs for five minutes, 35 seconds. All the video clips comprising this movie are in the MOV format. Maybe the difference in format is the culprit. What do you think?
Llewelyn (John Lambert)