This error message is often displayed when the users do not have the administrator rights on the computer or the installation is performed on a network computer.
To run installations on Windows 2000 or Windows XP computer, you are often required to have administrative privileges. The reason why installations require administrative privileges is that many installations modify the Windows registry and Windows System folders. If you are trying to install software on a computer in a corporate environment, you need to contact your system administrator to give you administrative privileges on your computer.