If you had got your UART PEX2S952 unit without any Latitude D820 driver CD or the latter is lost, you may choose to follow the links below. Without a special UART PEX2S952 driver to your unit, you won’t be able to use all its DELL functionality. The basic Latitude D820 driver from Windows is only able to support the minimum GeForce GTX295 set thereof. You are really in need of a fully-featured authentic Latitude D820 driver.
For UART PEX2S952 download, please just follow the EXPI9404PTG2L20 link.