Hi Catherine.
To disable touch, please ensure that your ActivBoard 500 series is connected to your computer.
Click on your ActivManager icon, and click 'Control Panel'.
Under the 'Pens' tab, when the board is connected you will see the option to disable touch. Please un-check the tick box to disable touch.
Below is a screenshot of what you will see.
I hope this helps.
I would recommend contacting Promethean Technical Support either directly via phone: http://goo.gl/tzNWci or use the contact form: http://goo.gl/pqrGC2 and mention the case number which I have created to help support the issue you are experiencing. Please quote 00425341.
Adam
Promethean Technical Support