Zoom the workspace in or out
In Microsoft Expression Blend, you can zoom your workspace to collectively increase or decrease the size of the workspace elements, specifically the Toolbox and panels. For example, you can shrink the size of the Toolbox and panels to create a bigger area for the artboard.
On the Tools menu, click Options.
Select the Workspace pane in the Options dialog box.
Adjust the Workspace zoom value (from 50 to 150) to the size you want. You can enter a specific value, or scroll through values by moving your pointer over the property's text box, and then dragging when the numerical adjust cursor appears. The size of your workspace changes as you adjust the value.