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Appearance > Folder Options > Thumbnails

Thumbnails

In folders containing pictures, Windows can display thumbnails of all of the pictures in the folder. You can specify how these preview pictures should look here.

Under Thumbnail size, you can specify the dimensions of the pictures. The default value is 96 pixels, but you can enter any value you want here.

Under Picture quality, you can use the slider to specify the quality of the thumbnails. The better the picture quality, the more disk space will be needed.

Under Cache, you can specify whether the thumbnails should be saved in a Thumbs.db file. This file is saved in the same folder as the pictures so that the thumbnails can be displayed more quickly when you access the folder again.