Originally posted by Protector
I think it says themes... not styles... what a shame... 
Don't get smart
"A theme is a set background plus a set of sounds, icons, and other elements to help you personalise your computer with one click"
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnwxp/html/xptheming.asp
Using Windows XP Visual Styles
Windows User Experience Team
Microsoft Corporation
May 2001
Introduction
Using Microsoft Windows XP, you can now define the
visual style or appearance of controls and windows from simple colors to textures and shapes. You can control each defined part of a control as well as each part of the non-client (frame and caption) area of a window. The user can then use the Appearance tab in the Windows Control Panel to switch between the classic
visual style and other available styles.
A
visual style is included with the Windows XP release. Using helper libraries and application programming interfaces (APIs), you can incorporate
the Windows XP visual style into your application with few code changes. For more information, see the Platform SDK documentation in the MSDN Library.
http://msdn.microsoft.com/library/d...shellcc/platform/commctls/userex/cookbook.asp
http://msdn.microsoft.com/library/d...s/shellcc/platform/commctls/userex/themes.asp
The common controls that are included in Microsoft Windows XP are based on the Microsoft Win32 common controls and user controls. This control set has a new functionality,
referred to as visual styles. The look and feel of controls can change based on selected system
visual styles.
What Are Visual Styles?
Visual styles are specifications for the appearance of controls. For example,
visual styles can define the color, size, and font of controls, and they enable you to configure the visual interface to coordinate with your application interface. Additionally, they provide a mechanism for all Windows-based applications to have
visual styles applied.
An updated
visual styles application programming interface (API)ComCtl32.dll version 6and an updated UxTheme library are provided in Windows XP to enable you to program
visual styles. You use the Theme API to
apply visual styles to your applications. This API provides functions for drawing, opening, closing, and retrieving control appearance information.
The common controls library, UxTheme.lib, is a rendering library that separates the visual element of a control from its functionality. Using this library, a control can retrieve its appearance from the current system
visual style without you writing specialized code.
UxTheme.lib is used by the common controls to take advantage of system
visual styles. ComCtl32.dll queries UxTheme.lib for appropriate dimensions, sizes, and other pertinent information for a control. The dynamic-link library (DLL) calls UxTheme.lib to render the parts of a control or surface. Using UxTheme.lib, you can define the rendering of icons, borders, controls, and other user interface (UI) elements.
You can take advantage of
visual styles capability and produce controls that query the system for visual
style information. The system UI modifies its appearance based on the visual
style specifications. To be able to use
visual styles you must have an operating system that contains ComCtl32.dll version 6. Windows XP ships with both version 5 and version 6. By default, all applications running under the Windows XP operating system use version 5 to maintain compatibility with earlier versions of ComCtl32.dll.
If you want your application to use ComCtl32.dll version 6, you must add an application manifest that indicates that version 6 should be used if it is available. Version 6 includes some new controls and new options for other controls, but the biggest change is support for the Windows XP
visual styles architecture. See the Using
Windows XP Visual Styles for information on how to create application manifests.
Using the common controls delivered in ComCtl32.dll version 6 applies visual
styles to your application; therefore you can tailor your application appearance to suit your audience. For example, the business and consumer releases of Windows XP might each implement a different visual
style to create user interfaces that distinguish the two releases. The Appearance tab of the Display window on the Windows 2000 Control Panel enables the user to change colors, fonts, and sizes of desktop elements. The new controls provide a way for applications to modify desktop elements in the same way; they enable the system to make changes to any control or window that has a visual
style applied.
Straight from the horse's mouth (Microsoft) itself. Nowhere does it say "theme" - only "visual style" (not even
visual theme, sorry)
... "I think it says
styles, not themes... what a shame"
