The CY3672-USB kit driver is not a signed driver. So during installation on 64-Bit Windows Vista and Windows 7 one might experience errors as follows:
In the case of Windows Vista 64-bit operating system the error message is “Windows cannot load the device driver for this hardware. The driver may be corrupted or missing. (Code 39)”
In the case of Windows 7 64-bit operating system it is "Windows cannot verify the digital signature for the drivers required for this device. A recent hardware or software change might have installed a file that is signed incorrectly or damaged, or that might be malicious software from an unknown source. (Code 52)".
Following are the steps to disable driver signature enforcement in 64-bit operating system
<!--[if !supportLists]--> 1. During boot-up press F8.<!--[endif]-->
<!--[if !supportLists]--> 2. In the list of options that appear select “Disable driver signature enforcement”.<!--[endif]-->