When it comes to customization first thing we do is change desktop wallpaper. If you have changed desktop wallpaper with your custom image before you may have noticed that its quality changes when you use it as a desktop wallpaper. This happens because when you set an image to your desktop wallpaper windows will automatically compress it to reduce image size so that it takes less space in memory. This feature was first introduced in Windows Vista. So go ahead if you want to control what happens to your image.