How to Text Message a Cellphone Using Your Computer's Instant Messenger

1. Log in to Windows Live Messenger, AIM or Yahoo Messenger.
2. Add a cell phone contact to Windows Live Messenger by clicking the 'Add' drop-down menu and then selecting 'Add a friend.' Insert a phone number with area code in the 'Enter a mobile phone number box.' Click 'Next' to add the contact. You do not need to add contacts in Yahoo Messenger or AIM to send a text message.
3. Click on the 'Friends' drop-down menu in Windows Live Messenger and select 'All.' Double-click on the cell phone number, insert your message and hit enter. In Yahoo Messenger, click 'Contacts' and then 'Send a Text message.' Insert the country code, +1, the area code and phone number in the 'To' section. In AIM, click 'File,' then 'New IM.' Insert the country code, area code and phone number.
4. Type your message and hit enter to send the message.