Window 7 has multiple layers of security and being logged in as an administrator does not always provide sufficient access to the system to successfully install all software. If the installation file is an executable, with an .EXE extension, you should always right-click on the file and select “Run as Administrator” from the context menu to execute the install. This grants an additional level of access to the system.
For example, a user reported that when they tried to install the latest version of GEOPAK they got the following error message "Failed to Set Environment Variable" and it would not install. After being instructed to right-click on the file and select “Run as Administrator” it installed successfully.