Have you done all of this:
Plug the MagicJack device into one of your computer's or laptop USB ports. The device is pre-loaded with the MagicJack software, which launches automatically when the device is recognized.
Plug the phone line connected to your telephone into the exposed edge of the MagicJack USB device. This handset functions the same when receiving a call as it does when connected to a landline telephone connection.
Click the blue "Register MagicJack" button on the MagicJack software.
Select the radio button next to the store from which you purchased the MagicJack device, and then click the "Next" button.
Enter your e-mail address and either your credit card number, order number or ZIP code if you didn't purchase the MagicJack from MagicJack's Web site or call line. Click "Next," and then choose to either create a new account or add the device to your existing account if you have one. Enter your personal information if creating a new account, or type your MagicJack's name and log into your current account if applicable.
Read the "Terms of Service," and if you agree to them, check the "I Agree" check box and click "Next."
Click "I do not want a phone number" if you don't want to be assigned a number. Click "Vanity Number" if you want to choose your own number. Click "I want a Canadian number" if you want to be assigned a Canadian phone number. Click "I do not want a Vanity or Canadian number" if you want a normal phone number; MagicJack will determine the last four digits of the number. Click "I elect to accept free outgoing service" if you want to make outgoing phone calls.
Check your e-mail for a confirmation message containing a login password. Click "Close Window." Enter the e-mail address and password XXXXX the login fields, and then make a test phone call to confirm that it is installed correctly.