Over the last 7 years I've set up more than half a dozen DSL/cable/FIOS modems and routers (I've moved a lot). I've always used Linux or OS X (which was as problematic as Linux in 2004).
FWIW, every company I've worked with (AT&T, Comcast, Verizon, others) has a method of activating everything that does not require installing any software. If you have a technician on site installing something they can do it for you; if not you may have to call them to do it.
In my latest round with Verizon FIOS (4 months ago), the technician let me know that they have the option "in case you just moved in and your computer is packed away." Use that as an excuse, or say you haven't purchased your computer yet but your family is over visiting and need to use the WiFi.