Thanks, I'm skeptical but I will try it tomorrow and let you know. For the record the machine's model is Samsung series 7 Chronos NT770Z5E-S78
I have followed the links that you provided and they redirected me to the Windows store where both 'Samsung settings' apps show up but there is no download link. Thanks a lot Roger for trying to help, but believe me I've been struggling for years, this machine was designed for Windows 8 and it took a year for Samsung to provide new drivers so I could upgrade to Windows 8.1 At the moment everything works except for those keys, it is not a problem as my wife will be using the computer and she couldn't care less whether those keys are active or not.