Toradex WindowsCE OS image comes with default on-screen keyboard, But the size of the default keyboard is relatively small.
However, there is a large on-screen keyboard available which is not a part of the preinstalled Windows CE licence.
Toradex is providing cab installer for testing large on-screen keyboard, but for volume production you need to upgrade your Windows CE licence.
For more information on license see Windows Embedded Compact License and Components
Note : In Windows CE6, the keyboard will pop-up at top-left corner of the screen.