When you attempt to install Adobe After Effects CS4 on Windows Vista 64, the installation fails and displays the following dialog box:
"Invalid User Credentials. You do not have sufficient security credentials to install Adobe After Effects CS4."
you are not prompted to authenticate with an administrator account, and using Run as Administrator gives the same results.
This error can occur when a standard (non-administrator) user attempts to install Adobe After Effects CS4 in Windows Vista 64 when User Account Control (UAC) is disabled.
Temporarily enable UAC and run the installer again.
To temporarily enable UAC, see the To enable User Access Control (UAC) section of "Disable User Account Control (Windows Vista)" (TechNote kb404888)