The Thomson modem is an ADSL modem. Which means it's an Asynchronous Digital Subscriber Line modem which is the most common for telephone line internet connections.
There really are no OS drivers for it as the modem is OS independent. At least that's what the tech specs stated when I looked at the PDF format spec sheet available here:
http://www.technicolor.com/en/hi/hom...icolor-st536v6
Routers and modems don't have "specific" drivers for various operating systems because they reside outside of the operating system itself. With your setup, the computer merely connects via the RJ-45 WAN Ethernet port to the same on the modem.
You might try turning off the modem and let it sit for about 30-45 seconds, (make sure your computer is turned off too) then turn the modem back on and let it go through it's self-test on power up and then turn on your computer. Sometimes this is necessary to get the router the recognize the new setup.
Try that and keep us posted.