a netgear router i assume ? exactly when is it asking for a security key ? did you purchase the router new or used? what model number.
There should not be a security key but there might be a password.
you should be able to access the router by using your browser and putting 192.168.1.1 or 192.168.0.1 in the address bar like a url and hitting enter
you should get a prompt for an id and a password. the default is
admin
password
if you mean security key for the wifi setup. that is something that you make up yourself in the router. it just has to match when you set the wireless computer to log into the router. this keeps strangers from using your internet connection. it is basically your own password. invent one and put it in the workstation computers when it asks the first time you connect to the router via wifi
C&onsultant
30 years in nyc computer industry working with PC and networks banks brokerage legal etc.