Adding Files to Your Posts and Pages with LiveWriter
Adding a file to your posts and pages with LiveWriter is rather simple after you add a “Plug-in” to LiveWriter. Here are the instructions for adding the plugin and adding files after you properly install the plugin.
Installing the Plugin to Add Files
Click on the “Add a Plug-in…” icon on the bottom right of your screen.
After clicking on the icon, you will be taken to a web page. Scroll down the page to find the plugin called “Insert File(s).” Click “download”
Follow the instructions to install.
After installing, you should close LiveWriter and open.
After opening LiveWriter, Maximize the LiveWriter window.
You will see the new icon called “Insert File(s)…”
Using the Plugin to Add Files
Click the “Insert File(s)…” link and a dialogue box will open.
Click the “…” to navigate to the file on your harddrive.
Add text in the “Text to appear as link:” field.
Hit “Insert” and you are finished.
Well…I did everything and my file did not upload 
The issue may be related to how your blog was set up. If the file did not upload, do this:
1) Select the “My Blog uses FTP” as well.
2) If that does not work, contact your webmaster and ask for instructions on how to configure the FTP settings.
