Most modern laptops no longer have a 9 pin serial port as the acceptance of USB for serial communication has become ubiquitous. Even though many devices now use the USB interface, there are still a number of devices that require an RS-232 serial link.
How do you connect an RS-232 device to a PC/Laptop that only has USB ports? Simple, use the Bafo BF-810 USB to RS-232 converter. This device plugs into the USB port on your computer and provides a fully functional 9-pin RS-232 port.
I like to do embedded development, particularly with the Microchip PIC family of devices. Because of this, I have had to acquire a USB/RS-232 converter device. Over the years, I have gone through several devices, but none have worked as well as the Bafo Technologies BF-810.
I purchased my device from Amazon.com. If you need a USB/RS-232 converter, this is the best one I have found!