people need to post their tricks here. the retail programs only do what you can do manually, but with a nice and easy console.
i don't use these retail programs as they use cpu/ram i cant spare when gaming and tend to cause software conflicts, instead i do it manually. getting free icon packs, images and the like and changing everything within windows. if you look around you can find the themes offered free, just need the instructions on how to manually insert and replace the existing ones based on OS!!
Some do, some don't. Don't forget that with WinXP Microsoft has essentially done the same thing as many of the themes type packages by adding a display layer to the OS. That is how, for example, you can switch back & forth in WinXP between the new look and the old "Classic" look. Programs like WindowBlinds from Stardock simply utilizes that existing functionality.