OK, so you mean wifi access point / router.
So which password have you forgotten?
The Admin account password for configuring the
"Little white box with flashing lights and ariel on it"
?
Or the WEP / WPA keyphrase?
If the former, others have suggested ways to reset. If the latter, you can use the admin account to set a new one, which you then need to apply to ALL PCs that you want to connect.
SD