OK - From here, solving this should be easy.
You have installed Windows enough times, and the modem does not automatically install correctly, so apparently Windows does not have it's own driver for that device. This seems clear now.
However, you have found FM56-P on the modem. This is in this case a model code that manufacturers sometimes (I think they always should) put on their products to make it easy to track down drivers on their web site.
In this case doing such is easy. Go to www.aopen.com
, click on the English (Global) version, then you will find a Downloads link (be patient; even with an ADSL connection this seems a slow site), then above the default list of drivers choose Fax/Modems, then you can even choose your exact model from the list (it is listed), and then a number of downloads will become available in the list including drivers for various operating systems.
So download the appropriate driver and follow instructions (if any, to install it). If you get stuck at this point it should be a lot easier to help you now than before knowing if you had the correct drivers.
As a shortcut for you, I have provided this link which should be you straight to the page you need:
Wishing you better luck now!!!