Welkin Numeric Pad not functioning correctly under Windows

I am using a standard Apple wireless keyboard together with a Belkin Wireless YourType Numeric Keypad for iMac and MacBook . Both work fine under OS X but in, for example, Excel under Windows any entry in the Belkin results in focus jumping about the spreadsheet or jumping windows. I assume therefore that a 'signal' is being received but that it has little similarity with the key pressed!

Any suggestions for getting the numeric pad to function correctly?

Peter H

 

@PeterRHawkes try to change keyboard settings to "Don't optimize for games" (VM Configuration -> Hardware -> Mouse and Keyboard)

 

I'm in the same situation as @PeterRHawkes.
This is my setup