Recover your wireless router's access password or network key by accessing the router configuration page, or you can do a factory reset if you've lost the admin password. If the password is saved on your computer, you can simply go to the security options and choose to show the characters in the password field.
To view an existing Wi-Fi password, click on the network icon in your system tray. Then, right-click the name of the network and choose the Properties button. Click on the Security tab -- it should show the security type, encryption type and password. Check the box to show the characters for the password.
To change a password for the router, open the router's page by typing in the IP address in your browser; this varies between manufacturers. Log in using the administrator account and password. Navigate through the options until you find the network profile. The options vary, but you can usually click the Edit option to access the network SSID and password. Change and confirm these options.
If you don't know the administrator password to your router, turn off all equipment and press the reset button on the router, holding it for about five seconds. When it boots up, use the information in the router's manual to set your information again.