about UART controller

I was trying to sync my LG KG290 to my PC with XP3 OS.

I was prompted that there was a new hardware installed and looking for driver. But my PC was not able to find one.

I checked on the driver manager and there was a yellow question mark requiring a USB UART Controller driver to be installed.

I dont know what is a UART controller. I thought XP has all the necessary driver for plug and play.

Please help!