I believe this still hasn't been fixed (at least for 3rd generation processors). If you read: Re: [SCALING BUG] Windows 10 / Intel HD Graphics 4600 - Impossible to get rid of 'Black Borders' problem - Stuck at 'Constrain proportions' post #19, it says that the feature is still being developed for Windows 10. I personally rolled back to Windows 8.1 until the feature will be added.
Thanks for response, but unfortunately I haven't enough time to rollback to Windows 8.1. NVIDIA and AMD released new driver few days after Windows 10 was released and Intel after 2 months nothing..
I am afraid that this type of processor with the graphic chipset does not have support for Windows 10