OHH DARN!.... curse my computer ignorance.....

It said to put in my IP Address (default IP Address); I did then a popup box came and said to put in the username and password.... the website you gave me told me what the default of that was as well, but i guess my router isnt set to the defualt.....lol...... I dont know what to put. How would I find out what my username and password is?