Before you connect to computer, make sure from the following:
1- The Service is enabled in your UIM card from the service provider.
2- Your account is not empty (you can make calls).
Then, please check the following points:
1- The handset (Brava Solo CS-570) is on and connected perfectly to the computer and not in the Storage mode.
2- The CDMA Driver is installed in your PC, so you will find the device in Device Manager as "" .... deagnostic interface ..... COM(x). If no, to install it from the included CD with your mobile phone or download it here
3- The dial up connection is using the mobile modem (in case other modems are available in you PC).