I have a Proline tablet running Windows 7 Professional. The client has added it to their domain, causing it to require Ctrl + Alt + Del to log in. They do not want to change this. If I plug a USB keyboard in, then the CAD combination works fine. Yet, when using the On Screen Keyboard, it has no effect. The problem is not that the touch is not working, the cursor follows the touch perfectly. At the end of the sequence, the cursor is hovering over the Del key, but the logon does not preceed.
Oh, and the screen reads; "Press CTRL + ALT + DELETE or use the Windows Security button to log on". Yet, the only button on the tablet is the power button.
What could be causing this and how do I fix it?