On both my pc & laptop after upgrading to 8.1 the number pad to the right of the keyboards failed to work properly, after much searching I found how to resolve the problem.
Go into the control panel & then into ease of access centre, scroll down to 'Make the mouse easier to use' under the section 'Control the mouse with keyboard' then uncheck the box named 'Turn on mouse keys' apply & press ok.[/quote
"123456789" thanks.. this worked,