I'm having the same issue with the Keyspan adapter. The serial assistant still doesn't find the adapter. I tried adding legacy hardware in order to get the Ports (Com) grouping in Device Manager but there is nothing to find so it won't add. I also followed Tripp-Lite instructions below to manually add the driver for Windows 11 Pro and the adapter assistance still can't see the adapter. I assume since it can't be seen that there isn't an old driver to remove as the last paragraph states but I did delete the adapter which was listed under "Other Devices" to try to delete any old drivers before performing the instructions below.
Tripp-Lite instructions:
Windows 11 Pro
1. Do not initially attach the device.
2. Download the correct driver from the product's support page on
www.tripplite.eaton.com and unzip the driver into a folder of your choice.
3. Locate and open the Device Manager program from your computer's system tools.
4. Using the menu at the top, choose "Actions | Add drivers".
5. Browse to the folder where the driver is located, OK the installation.
6. Connect the device to your computer's USB-A port using the included cable.
7. Open Device Manager. The device should be correctly identified and have a driver available.
When downloading the most recent driver for this product it is important that the previous driver be manually uninstalled and removed from the computer. If the old driver is not removed the Device Manager will still attempt to utilize the old driver despite the presence of the new driver.
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