Windows only knew a few video encodings back then. Later folk created CODECs to add more but as you have discovered these can fail on some files. There are no plans to fix this as most CODECs are not from MSFT and XP's fixit team is long retired.
You may want to change the icon of the file manually or research titles like CODEC SNIPER and look for fixed codecs.
There are other reasons for this and it's a cache limit or a corrupt cache. Here's two googles about each.
I run WinXp SP3. I create video files using Adobe Premiere Pro 1.5 in HDV AVI format, Each clip is stored as a separate file. The video frames are 1440x1080 pixels with a Pixel Aspect Ratio of 1.33.
When I look at these files under Windows Explorer in Thumbnails view, I sometimes get the first frame of the clip as a thumbnail but sometimes I don't. I get Instead a generic "AVI" picture. I haven't been able to determine what causes the Explorer to display the first frame of the clip as the thumbnail instead of that generic picture.
Is there a way to force the Windows Explorer to always use the first frame of a video clip as the thumbnail picture?
I have tried to use the "Refresh Thumbnail" entry provided by the right-click menu but that does not do anything.
Showing the first frame of each clip as a thumbnail would be extremely helpful when managing a large number of video clips.
Any help on this would be much appreciated.