This card capability allow for upgrade with additional serial cards to your computer easily. Note: Open the "CH38XDRV"file in the CD to install. 2 x 16550 Fast Uart serial port, data transfer rate support up to 115200bps. Plug and Play, Automatically selects IRQ & IO address, Supports IRQ sharing. Compliant with ExpressCard/34mm Standard; Compatible to 1-Lane (x1) PCI-Express Throughput. Operating System: Windows 32bit 2000/XP/2003 Server/Vista and 64bit XP/2003 Server/Vista/WIN7/WIN8/WIN10 / Linux. If there was any problem with PCIE 2 port serial expansion card, pls feel free to contact us, we will provide a solution within 24hrs.