said by scooper :

Do some reading in the manual about "Secure Easy Setup". Yes , it is an electronic manual (PDF I think).

said by Thane_Bitter :

They might have included the product manual on the CD, however the disc is more functional as a coaster. Everthing can be configured throught the routers GUI anyways.

Note: SES adds the ability to connect wireless clients to the network automatically. SES is only available to SES compatible adapters.

Orange - SES functional but no clients are connected using this feature,

Flashing White - SES active and seeking clients (this occurs after the SES button has been pressed, this mode will last for up to 2 minutes),

White - SES has successfully configured a client to the access point.

SES is only usefull if all of your other wireless devices support the feature. In a mixed device enviroment you will have to set things up the old fashion way but entering the key on all of the clients.

Using DD-WRT firmware the function of the button, and the lights can be changed, for example the button can be changed to turn the wireless radio on or off.