Hi there,
I'm Ramesh, here to answer your query at the Microsoft Community.
FTD2XX.DLL is not a Windows system file. It's part of the FTDI drivers from Future Technology Devices International Ltd.
What's the name of the software you're trying to run? You may check with its official support to have the dependency installed.
The FTDI site has a copy of the drivers (which includes FTD2XX.DLL) that you may try:
D2XX Drivers - FTDI:
https://ftdichip.com/drivers/d2xx-drivers/
Direct download: