C-3700

> C-3700

   C3700[v1] or C3700v2?  Look for "Model" on the product label.

> Where can I find a PIN# on this router?

   To do what, exactly?  If you mean the router's WPS PIN, then visit
http://netgear.com/support , put in your (actual) model number, and look
for Documentation.  Get the User Manual.  Read.  Look for "WPS".  Keep
looking until you find "Specify WPS Settings".

   Regarding "PIN#", see: http://antinode.info/complaints/aer.html

> https://kb.netgear.com/31575

   That KB article deals with the client-device WPS PIN, not the
router WPS PIN.

   Terse questions can waste more time than they save.