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do the following
With the router powered on.. Turn the router around.. There is a small small hole.. Inside that hole is a reset button..
You will need something small like an unfolded paperclip, or, sometimes the tip of an inkpen will work.
Press into the hole, and press the reset button inside the hole untill the routers lights flash at once for a second together, then go out..
Once this is done, unplug the router, then plug it back in ( power cord)
The router will be reset.
Then. to set a wireless password
On a computer connected to the linksys now.
Click the link belowClick Me!!
On the page that comes up, it will ask for a username and password.
type in admin for the password, leave the username blank
You are inside the router..
Click on wireless, then right under it click on wireless security.
Where it says authentication, click it and change it to wpa2 psk
Where it says, PSK / Passphrase / Or Network key .. There is a text box to the right
In that text box is where You will have to type in a new password, and click apply / save settings.
Then.. The router will restart..
You have now set your wireless password.