The Windows Automation API library enables accessibility tools, test automations, and pen services to access a standard user interface across operating system versions.
Do you know applications that use Windows Automation APIs can significantly decrease Microsoft Visual Studio IntelliSense performance if Windows Automation API 3.0 is not installed? For example, the Windows pen and touch services can significantly decrease Visual Studio IntelliSense performance if Windows Automation API 3.0 is not installed.
You can download the update from http://support.microsoft.com/kb/981741. This update is available as a stand-alone download for 32-bit editions of Windows XP and for Windows Server 2003. This update is not available for 64-bit editions of Windows XP. The Windows Automation API is a component of the platform update for Windows Vista and of the platform update for Windows Server 2008.