Creating Windows XP Icons
Microsoft MSDN contains a 19-page document that discusses how to design and create colorful and dynamic icons for Windows XP using a vector program, such as FreeHand or Illustrator, and Photoshop.
Microsoft Windows XP introduces a new style in icon design. The guidelines in the document walks you through the steps of designing and creating Windows XP-style icons.
The Windows XP icon style is all about fun, color, and energy—and, as there are now 32-bit versions of the icons, smooth edges. Each icon is rendered in a vector program and then manipulated in Adobe Photoshop to create a beautiful image.
According to Microsoft, the guidelines are geared towards designers and they recommend you work with a good graphic designer, especially one with experience in using vector or 3D programs, to create your images, like the ones shown below.