Hi there and welcome Shirley
Can you in windows live mail, click on name of your account from the left-hand menu, then click on the 'Accounts' tab. Click on the 'Properties' button
Go to Advance then outgoing server and make sure it is set to use Authentication and use that of the incoming server
Once done you should then be able to send again.
I can also do these steps for you, and have made a request via Additional Services. This is optional, and if you choose to do this, I can, with your permission, remote into your computer while you watch and do all these steps (and deal with any problems that arise during them) for you. Or if you do not choose to take this service, we can continue here. This is no problem at all. Just let me know please.
Else let me know the results please.