By saying that there is no Windows skin with transparency applied I meant - CSS transparency (opacity and alpha filter), however here are a few skins - Vista and Widnows7 that are using transparent sprite images, and that could not be changed, as this is by design requirements, as both Windows designs have some transparency and that`s why our embedded skin have also.
If you want to remove the transparency from the sprite images, yous should create custom skin
based on Vista and to use non transparent sprites. Byt you should be careful in which parts of the sprites you will remove the transparency as it is necessary for the shadows.
My advice is to use another not transparent skin instead Vista.
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