Program might not have installed correctly" warning dialog in Microsoft Windows 7 (64-bit)

Why am I getting a "Program might not have installed correctly" dialog box when installing Pharos Blueprint Tracker 4.2 on Microsoft Windows 7 (64-bit)?

The Pharos Blueprint Tracker 4.2 install and uninstall packages have been designed to be compatible with the User Access Control (UAC) and Program Compatibility Assistant (PCA) in both Microsoft Windows Vista and Microsoft Windows 7. However, a bug in Microsoft Windows 7 64-bit can produce an erroneous PCA dialog box during installation of an application. This dialog box states that the "Program might not have installed correctly" and provides options for making the installation compatible. This bug is described in detail in Microsoft KB 978637 (http://support.microsoft.com/kb/978637). This typically only presents itself when the installer is initiated in a 32-bit context, such as may be encountered with many software deployment systems using 32-bit client endpoints.

More often than not, applying the hot fix described in KB 978637 is sufficent for removing the spurious error and deployment can resume (note that this hot fix requires a workstation reboot). However, in some instances when the hot fix is installed, a "This update is not applicable to your computer" message displays and installation will not continue. This hot fix requires that the workstation operating system be validated against Windows Genuine Advantage. If the workstation is not verified, this hot fix will not install. On a workstation-by-workstation basis, this can be done by visiting Microsoft's "Genuine Microsoft Software" site at http://www.microsoft.com/genuine. For larger populations, please consult your Microsoft reseller.