In the Media Pool
in category 
Video, right-click the corresponding
video file and select Properties.
Remove the checkmark next to Create display data automatically and click OK.
Usually, display data are generated when videos or sequences of images are added to video tracks. However, you can also influence creation of display data. This may be useful in the following cases:
Exempting certain videos from display data creation ...may be useful for presentation videos (mixdown of the entire show) as they usually need not be edited any more, i.e. display data are not necessary. Therefore you can exempt display data creation for certain video files.
Create display data for individual videos ...may be useful if you want to use display data for presentation (instead of the original data) or if display data are to be used for rendering new video files.
In the Media Pool
in category Video, right-click the corresponding
video file and select Properties.
Remove the checkmark next to Create display data automatically and click OK.
This way, this particular video is exempted from automatic or global display data generation. If you find out that you need display data for this particular file at a later time, you can remove the checkmark again.
Under Project
Options - Display
data you can choose wether the display data are to be created
automatically or not.
If you want to recreate display data for individual videos or picture sequences do as follows:
In
the timeline, right-click the corresponding video object and select
Special Functions 
Recreate display data. Following
this the old display data will be deleted and new ones created.
Alternatively, you can also choose option Create/update display data, following which the required display data will be checked and only recreated if necessary.
If you want to recreate display data for all video files, you need to delete the older display data versions followed by selecting the main menu item Media Pool - Create display data. See also Deleting display data and Creating display data for media files.
The display data are saved to the same folder as the original media files but in a subfolder called .w5 When color profiles are used for the output devices folder .w5 may contain further subfolders named in accordance with the color profile, which in turn accommodate these special display data.