No Device or Unknown OS problem in Banglalion
If you have an old modem or purchased a refurbished one like Model: WU216 it may not work on Windows 10, Windows Server & other OSs.If your modem not working then you may want to try this solution.
Solution:
If your modem software showing No Device or Unknown OS then,
Uninstall the Connection Manager and install a different version of CM given below
Banglalion CM Alternative Download
Do not use two Connection Manager in the same time. It will conflict.
I personally talked to a Banglalion Customer Manager & there is no other solution for this. If this does not work, you may have to upgrade to a new Modem.
N.B: It may take little more time to find the device by CM, so be patient & hope for best.