Auslogics Visual Styler
If you're looking for a simple, visually appealing way to dress up your PC, Auslogics Visual Styler is worth the download. It offers plenty of ways to customize the way Windows looks. It gives you instant access to many deeply hidden Windows customization features, and adds some twists of its own. So, for example, it will let you change the resolution of your icons, their size, the space between them, and even whether there should be a shortcut arrow on them. You can also change which desktop icons to use for Internet Explorer, the Recycle Bin, drives, folders, and so on. There's also a wallpaper changer that will change the wallpaper used every time your PC starts.
There's plenty more, including a simple way to download and use wallpapers from the Internet. This program won't let you change Windows to the same degree that a program like 3DNA Desktop does. But if you're looking for an easy way to change common Windows elements, it's a good bet.