If you have noticed in Windows Phone 7.5 , the availability of the Show Caller ID and “Call Forwarding” in the settings page but somehow the “Call Waiting” settings was missing in the settings UI .
You can enable or disable the call waiting feature in Windows Phone by dialing the following service code
To enable the call waiting feature in Windows Phone 7 , type the following in the dialer and press call
*43#
To disable the call waiting feature in Windows Phone , type the following in dialer and press call
#43#
