Sorry for my bad english, i'm french
Same issue ! i cannot adjust screen because desktop exceeds screen, my taskbar on windows is cutting.
I have an old plasma Panasonic 42 PX 71 EA and my resolution is 1280 x 720 , i test with an another Tv Samsung recently and same problem except on recently TV you have option to autoscan and adjust it.
I encounter same issue with ATI and Nvidia and on both software you can adjust display scaling or with Intel HD graphics control PANEL you don't have option to custom resolution !
I have Maintain display scaling or center, that's all and i can do anything .
It's just amazing that in 2015 we cannot use this function who is currently in existence with another manufacturer or with my PS3 for example.
I found many hours but i don't understand