For some unknown reason, my pc won't go into stand-by. It will re-start and shut down only. I don't know if it has always had this 'fault' (it's 1 yr old) as I don't usually have a need to put it into stand-by, until today.
Are your graphics card drivers properly loaded ? Right click on a bare piece of desktop and select " properties , then settings , see if the card is correctly listed , and if necessary reload or update the drivers , in fact , update the drivers anyway , that is usually the case .
When booting in to safe mode with a bare minimum of drivers this is exactly the same thing you get , shut down and reboot only , because the drivers don't load .