Before downloading drivers, check your cable. Most "409.1" cables sold online have a transparent blue plastic casing near the USB connector.
Sometimes running the installer isn't enough, especially if Windows has already tried (and failed) to install a generic driver. You may need to force the update: Vag Kkl 409.1 Driver Windows 10 Download
Do not download drivers from random "driver download" websites; they are often bundled with malware. Go to the source. Before downloading drivers, check your cable
Note: If you have a very old cable (rare), it might use the Prolific PL-2303 chipset. If the FTDI driver doesn't work, repeat the steps above but download drivers from the Prolific website instead. Note: If you have a very old cable