Not able to get email signature while sending Replies and Forwarding mails.

Follow below steps to resolve your issue.

 1 - Open Windows Live Mail client.
 2 - Click on File menu at the top.
 3 - Then select Options > Mail... , Which will open Option window.
 4 - Now, Click on Signatures tab at the top.
 5 - There, under signature settings UN-check “Don’t add signatures to Replies and Forwards”. 
 6 - And click on OK.

You may also follow the screen-short below for help.