Help, network crashed? :(

If you press the reset button on a router it goes to the factory defaults which may not include the settings you require -- including the security passphrase you may have already applied to the router and your computers' wireless adapter.

Suggest you start by turning off firewall in computer and connecting to the router via ethernet cable and get into the router's user interface (see router manual for how).

Once in disable all wireless security measures temporarily (including Access List).

You don't say if you are on Cable or ADSL service but see if your ISP has help files on its home site have a look at WAN settings in router and see
if settings match your ISP's requirements. You may have to ring a help line otherwise.

Once everything is working apply wireless security in router (and then in computers) and re-enable your computers' firewalls,