Click on the views tab then select thumbnails?
There's a bug in Vista that stops it remembering folder views IIRC. Might be in vain setting up anything now to have it change by itself later on.
Try Right clicking a folder, click the customize taband then under the 'what kind of folder you want' click pictures and videos.
If this works, go to the top level folder and do the same ensuring the 'also apply to subfolders' is ticked.