Pressing the button on the back, usually labelled with the word RESET deletes the settings, so its back to its factory default state. The default state's exact settings depend on the device, but if it a lyksys or netgear the new name of the wireless signal is the brand of the device.
I would suggest connecting your laptop directly to the router to reconfigure it, that way when you change the settings, you won't lose the admin console.
To get to the admin console, you need to enter the IP address into a browser window. Frequently, its 192.168.1.1 or 192.168.0.1; but to be sure pull up your internet settings and find the IP of the router there (sometimes listed as the gateway on different versions of windows). IF it requires a password, again it depends on the brand by admin and password are popular defaults.
Note: CHANGE THE DEFAULT PASSWORD TO CHANGE SETTINGS. IF you don't then anyone on your network can change those settings, and you don't want them to.
Once you're in the console, just change the wireless name, add a password (WPA please! WEP is not very secure), apply settings; then on your computer- tell it to join the network you created.