Steps to attaching a file in forum posting.Step 1: Click on the blue REPLY button in any forum topic (location at the top right side).
Step 2: Click on the "+ Attachments and other options" link (see image below)
Step 3: Click on the "Browse..." button and select the attachment file from you computer (see image below)
Step 4: Compose your message and click on the bottom right "Post" button