The Current RealPort 4.5 driver does support Windows 7 64bit. I have seen that error code 14 when installing a old version of RealPort in Windows 7.
Here is a Link to the RealPort 4.5 driver:
RealPort 4.5 driver
Go to the Driver section and select Windows 7 for the operating system. Then click on the top link which is the RealPort 4.5 driver.
Thanks