(Q-01) When you said the keys "suddenly stopped working", does this mean immediately following the upgrade to Vista?
(Q-02) Does the keyboard work properly still on an XP machine?
(Q-03) If you haven't done so already, please, connect the keyboard to a computer w/ XP installed and see if the issue persists.
Did the issue follow the keyboard to the computer running XP?
(Q-04) Is
THIS the software you installed?
(Q-05) Before the operating system upgraded to Vista, was there software installed for this keyboard?
(Q-06) If so, did you UNINSTALL that software b4 INSTALLING the new software?
(Q-07) Is
THIS the keyboard?
(Q-08) If so, where are the keys located that you are referring to?
Are they on the 10-key pad to the right? (section (3)?
ASSUMING THAT THE KEYBOARD WORKS FINE ON A SYSTEM RUNNING WINDOWS XP, PLEASE, PERFORM THE FOLLOWING STEPS:
(09) If you didn't uninstall previous software for that keyboard, uninstall the software you just installed for it.
(10) Next, if possible, uninstall the previous software that was for the keyboard, too.
(11) Next, re-install the new software.
Please, post back w/ your results, findings, observations, etc.