I use Windows Live writer to write the blog. Very often, I copy paste the screenshot and paste to the Windows Live Writer. The default size is always small which I have to manually change to medium to fit into the post. Click the extra Button to change the size is fine but when I need to do thousand times, it become annoying.
There is a way to set the default behavior .
1. Copy paste the first image and adjust the size just like you normally do.
2. Click the <set to default> button
From now, on, all the pics you copy , should be use the same setting.