well now, the User's Guide is nothing but a Quick Start and leaves 99% of the details out

Your CD should have it and also something call VPN Lite
the default router address is documented to be 10.0.0.2 but gives no userid/password;
apparently not necessary (gulp!).
If you CAN access the configuration data, then you are looking for the WAN side information,
which will have the
Gateway address and
two DNS addresses;
please report all three
poke about and find the
1) Remote Control and clear the box [ ] allow remote config
2) Disable UPnP
3) find the page that allows changing the admin password; set it the same as your PC password.
4) save the config and if not done automatically, restart the router
(disconnect power, wait 30 sec, reapply power).