If your talking about changing the password on your wifi router you can try this.
1. open up cmd and type in "ipconfig" (without quotations)
2.Find the default gateway entry and enter that address in to your browser usually http://192.168.0.1/
3. If you haven't changed settings before the username should be admin and password should be password
4. You should be able to navigate through the settings to fine wifi passkey as the location will be different for every company