Have changed cables but still no configuration allowed.
Please take a look at article 10419 on http://www.PrometheanKB.com for USB troubleshooting issues.
Should you still have any issues I would recommend contacting Promethean Technical Support directly for full troubleshooting.
A list of contact numbers can be found: http://www.prometheanworld.com/us/english/education/support/technical-support-numbers/
Alternatively you can fill the contact form below to contact us via email.
In either instance, please quote reference number 00483126