The ActiveX Installer Service in Windows Vista @ TechNet
 

*Source: TechNet (http://www.microsoft.com/technet/tec...default.aspx)*
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It’s always the same story. To substantially enhance your security, you have to give up some freedom or flexibility. If your environment is like most organizations, you have a very strong desire to harden the desktop operating system in an effort to provide a more secure computing environment for your end users. IT administrators typically approach the task of securing the desktop by employing a combination of security policy settings, user permissions, file and registry access control lists (ACLs), and system service restrictions.

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