This driver is for the Prolific USB to Serial Converter. I have tested this driver with Windows2000, WindowsXP and Windows2003 and had no issues. The disk claims to support 95/98/me as well, however I have not tested this as I would not even touch those operating systems anymore.
This driver definately works, and I had to hunt around for a while in my stuff to find it. I realized how hard it was to come by and noticed how many people were looking for it so here it is.