Hi and Welcome!
Have you already read the FAQ?
I have a GSA-5169D External DVD writer and have lost the original disc that came with the unit. Can anyone direct me to the drivers for this writer as I can't find anything on the LG website(s)?
If you are running Windows 98SE, then you need drivers for the external enclosure, but I am not sure, if LG provided Win98 drivers with that drive, as Win98 isn't supported anymore. You might then try the drivers offered for older external drives, like the 5163.
In case you are running any newer flavour of Windows, starting with WinME, the required USB mass storage drivers are already present.