I have a multi-mode controller, which communicates via a serial port (RS232) to the computer. In my new computer (Win7 / 64bit) no RS232 port was there. That's why I had first operated a "USB to serial" adapter. Here there have been communication problems with the controller. After installing the PCI Express card with 2 serial ports on the controller now works correctly. Installation went smoothly, card installed in an available PCI Express slot. Map was detected immediately after booting, installed drivers, rebooted, both serial ports were available and configurable. Could not be better. Therefore, full marks.