b44720d5__Installer_3_7___Release_Notes__Known_Issues
[Component] Installation: Windows 64 bit Operating System [Change Request] N/A [Known Issues] 
Unable to install products under C:\Program Files in 64 bit Windows. When a user tries to install an application into the 'C:\Program Files' directory in a 64 bit operating system, the OS/MSI will convert it to 'C:\Program Files (x86)'. In this case the install location path in QI is different from the actual location. This will mean that the customer will not be able to uninstall the application using the Quest Installer. Workaround: Use the 'Add and Remove Programs' option within the Control Panel to uninstall the application.
Quest Installer 3.7 – Release Notes
Known Issues